2022 Husqvarna FC250 Suggested Settings/Mods

The 2022 Husqvarna FC250 has been in heavy circulation the past couple months and we have come across some settings to get you comfy as well as some mods that can help you get some more power out of the white stallion. 

TC Two-Stroke Air Filter Cage: This is the cheapest and easiest way to get more throttle response out of your FC 250. You will notice better throttle response through the low to mid RPM range by simply going to a TC two stroke cage with no backfire screen. Here is the part number you will need. P/N 5040601600

FMF 4.1 Full Muffler System: To me, FMF makes the best muffler system for the Husqvarna FC250. There are some other companies that have other bikes dialed in more, but on the Husqvarna, FMF has got it down. You will get more low to mid RPM response as well as more mid range pulling power. Top end is increased plus the over-rev is as good as stock. It is one of the few times that I was impressed because it was actually better than stock in almost all areas. The downside is that you must keep up on muffler packing (every 10-12 engine hours) because the FMF will blow out and that could damage your expensive titanium can. Did I mention that you will lose almost two pounds with the titanium 4.1 system? If you slap spring forks on your Husqvarna, you will be gaining almost three pounds. You can get most of that weight gain back down with a 4.1 Titanium FMF Muffler system.

Pro Taper Handlebars: But Keefer they come with Pro Taper’s! Yes, I know but now that PT offers the “Race Team bend” (810mm width, 91mm height, 49mm rise, and 52mm sweep), which is a little higher of a bend than the stock Husqvarna PT bar and is still a pretty straight. I do cut the Race Team bend down to 805mm as that is the happy medium for me and my 5’11 frame. The Pro Taper SX Race bar worked well for riders from 5’8 to 6’1 as well. Both bends come in a crossbar or crossbar-less style and the SX Race bend has a 800mm width, 87mm height, 54.5 rise, and 54mm sweep. If you’re looking for a better “stand up feel” from your FC250 look for handlebar close to these measurements.

Throttle Tube: There are a couple you can choose from here… If you’re looking for an aluminum throttle tube that is expensive, but helps the feel of your throttle, I recommend the ZRT throttle. This throttle tube makes the pull have almost zero drag and is a tough SOB. There is some set up/prep time to this throttle (cutting the right side of the handlebars), but it can help the pull over the long haul. If you’re more the plastic style tube type of rider, look at the Motion Pro Titan tube as it’s tough for a plastic tube and doesn’t have as much drag as the stock lock on style ODI grip/tube that comes on the stock FC’s. The stock plastic throttle has a lot of friction and gets tough to turn too quickly. 

Ride Engineering One Piece Bar Mount: The Ride Engineering One Piece Oversize Bar Mount has a one-piece top that is designed to resist bending much better than the stock bar mount. Precision machined from aircraft quality aluminum, there is also a 6mm difference between the forward and back mounting positions. Ride Engineering also machines their own stainless steel posts that prevent over tightening, unlike some other competing brands that DO NOT use quality posts. This bar mount has saved my son and I a couple times when we are out doing motor. He seems to crash a lot in corners and the stock mount on the FC250 just twists and bends easily.

Rear Axle/Axle Blocks: Going to a Works Connection Elite axle block kit or Ride Engineering axle block kit will get rid of the fixed left axle block on the stock KTM’s axle. This will help the rear end to move more freely under throttle and improve the shock’s comfort on acceleration chop. Both are great, but you will have to decide if you want a complete axle/axle block kit like Ride Engineering’s  or just the blocks themselves like WC’s.

Rear Brake Pedal Spring: Purchase a Honda CRF450R rear brake pedal spring with the rubber around the spring. The FC rear brake pedal spring vibrates and will break every 4-5 engine hours. Orrrrrrrrr. Get a Fasst Co rear brake return spring and be done with it! Fasst Co’s rear brake return spring offers tunable pedal resistance and a more controllable feel by placing the spring in compression instead of tension, minimizing the "on-off" feel of most rear brakes.

Fuel Filters: If you’re a FC owner, do yourself a favor and put a couple of these in your toolbox just in case. Fuel filters can get clogged on all FC’s and this can cause damage to your fuel pump or possibly not allow your bike to start properly.

Throttle Cables: If there is one thing that DOES NOT last on KTM’s/FC’s it’s the throttle cables. Every 20 hours or so I will have to replace the throttle cables to ensure that my throttle doesn’t feel hard or sticky when twisting. Originally I thought my throttle tube was dirty or maybe the right side of the handlebar had dirt on it, but I found out through a couple KTM mechanics, that the throttle cables simply wear out. You can’t lube them or clean them out as it will only make the throttle feel better for a short amount of time.  

Check All Spokes: KTM/FC spokes always come loose near the rim lock so make sure you pay attention to all the spokes after every ride. If you don’t check them constantly you will lose or break a couple. 

Check Engine Mounts/Swingarm Pivot Bolt: Always check the torx bolts that hold the top engine hangers on the bike. After break in, these will loosen up a bunch, so you might need some blue Loctite on the threads. After you do this, please continue to check these as they still back out from time to time. The torque spec on these bolts are important to the ride attitude of these FC’s. Also the FC come with frame guards and that means you will not know (until it’s too late) when your swingarm pivot bolt  backs out. Take off your frame guard and check pivot bolt regularly. While you’re at it, get the Acerbis frame guards as they last longer and have better grip than the stock ones. 

FI Indicator Light: The little FI indicator light bulb will fall out of the rubber casing as soon as you get past 10 hours. The best thing to do is put a little silicone inside the rubber casing, so the light bulb as well as the wire doesn’t flop around. 

Connector Behind Front Number Plate: If your FC or KTM is cutting out or maybe not starting, check behind the number plate for this connector. It could be unplugged or corroded from condensation. Hardwiring the wires/connecter is the best way to ensure that it doesn’t come unplugged. You can even using a two post connector instead of a four post as that can work as well. If you’re turning your handlebar to the right and your FC will not start, chances are it’s the starter wire being kinked or pulled too tight. Pull the sheathing away from the cables and inspect to see if it has come apart.

Suspension Settings:

RIDER WEIGHT: 150-185 POUNDS

Fork: 

Spring Rate: 10.7-10.8 bar

Height: 5mm

Compression: 12 clicks out 

Rebound: 9-10 clicks out

Shock:

Spring Rate: 42 N/mm

Spring Rate For 175 Pounds And Up: 45 N/mm

Sag: 102mm

High Speed Compression: 1.5 

Low Speed Compression: 9 clicks out

Rebound: 10 clicks out 

2022 Yamaha YZ250F Baseline Settings

The 2022 Yamaha YZ250F doesn’t have the changes on paper that you would like, but the bLU cRU did do some minor updates to help try and lighten the YZ250F up some. Yamaha lightened up the hub, sprocket, chain and they installed a 2.15 rear rim (instead of the 1.85 2021 rear rim), as well as went to Dunlop MX33 tires with a 110 rear tire in stock trim. The fork’s low speed damping was increased to try and create less pitching off throttle and there you have it. The 2022 YZ250F. Here are a couple baseline settings to try out on your own in case you might be lost.  

Suspension:

The 2022 suspension feels firmer (compared the 2021), holds up more in the stroke slightly, yet still has that KYB free feeling movement (unlike a Showa feel where it moves less with a dead feel) that is very active on the track. That active feel translates into a a front/rear end that follows the ground well under small chatter and bigger/softer braking bumps. I did have to go a little firmer still once broken in on both ends for my style of riding, but it didn’t take long at all to feel comfortable. Track Toughness of the 2022 Yamaha YZ250F is as good as the 21, but if you’re north of 185 pounds you might want to drop in a set of heavier fork springs 48N/mm fork springs and live happy! 

Fork:

Spring Rate: 47 N/mm (Over 185 use 48N/mm springs)

Height: 4mm

Compression: 8 clicks out 

Rebound: 10 clicks out 

Shock:

Spring Rate: 56 N/mm

Sag: 104mm

High Speed Compression: 7/8-1 turn out

Low Speed Compression: 8 clicks out

Rebound: 9 clicks out 

Mapping: 

If you’re looking for less engine braking and/or more mid-top end pull here are two maps to choose from.

Mid-Top End Map

FMF 4.1 Titanium Slip On Muffler System: Although the stock exhaust is VERY hard to beat in terms of performance, it can get a little raspy once you hit around 10 hours. Yes, that quick! The FMF 4.1 slip on system gives the bike a throaty tune and a factory look, but with a tunable engine character. We have found that running the system without the spark arrestor insert takes away too much back pressure, which causes the YZ250F to lose some of that bottom end power we come to love out of this bike. We prefer the system with the spark arrestor installed because it helps keep most of the stock bottom end, keeps the YZ250F quieter the bike, and can even make it legal to ride on the trails. Going to this will NOT give you more bottom end than the stock system, but you will get more mid range pull as well as more top end. Not to mention a much better muffler pitch!

2022 KTM 450 SX-F What Would You Do?

People always ask, “what would you do to your own bike”? Most of the time that question gets answered at the track or through email, but I thought I would put it out there for the world to see through my site. The KTM 450 SX-F is one of my favorite bikes to ride and race. In stock form the 2022 KTM 450 SX-F has an easier to ride smooth roll-on power than other 450s in its class and that lets the rider get on the throttle sooner through corners. The stock suspension is decent but needs some better lean angle front end traction, more consistency in the front end and more hold up (high speed compression) on the shock. Not all of my builds need to be extravagant, so I thought why not build a machine strictly on what the bike “needs” to make it even more fun to ride/race. Below is a parts list that I have created on parts that I strictly wanted personally on my 2022 KTM 450 SX-F. Since the 22 KTM 450 SX-F is virtually unchanged from the 2021 version, there is no need to do a FIRST RIDE! 

Parts List: 

 FMF 4.1 

Titanium 4.1 Muffler System 

Fmfracing.com

WP/REP Pro Components

CV Fork Re-Valve (REP Spec)

Trax Shock (REP Spec) 

1mm Longer Shock Shaft

REP Knuckle/Rods

Repsuspension.com 

KTM

Factory Split Clamps

Ktm.com

Vortex ECU

Mapped By XPR Motorsports

XPRMotorsports.com

VP Racing

MR PRO 6 HT

Vpracing.com 

Pro Taper

EVO SX Race Bend

Protaper.com

 Dunlop

MX3S Front Tire (80/100-21) 13.5 PSI

MX33 Rear Tire (120/80-19 12.5 PSI

Dunlopmotorcyclestires.com

ZRT

Zero Resistance Aluminum Throttle 

Zrtthrottle.com

Twisted Development 

Exhaust Flange

Td-racing.com 

Although this parts list isn’t long, it is distinguished. The REP Pro Component suspension done up by Mark at REP has given me a lot more confidence in pushing this KTM 450 SX-F in longer motos under rougher conditions. REP has some unique parts that go inside the WP Pro Components which they make personally. The Pro Component (Cone Valve) fork now gives me more lean angle grip through corners and added comfort when the track gets rougher. I couldn’t say that with the stock AER fork, because it wasn’t consistent like this spring pro component REP fork. I always had a problem with my KTM’s riding rear end low, but with REP’s longer shock shaft accompanied by their linkage system, my new Garage Build has a balance that I have never had before. To go with my newfound balanced suspension package, I turned to Chad at XPR Motorsports to tune a programmable Vortex ECU for more excitement down low yet keep that stock linear character that I like so much. With the ECU installed along with Twisted Development’s exhaust flange the KTM now has a controlled snap out of corners that gives me the ability to hop over bumps better as well as gives the KTM a lighter feel. Did I mention it revved out like a 250? Yeah, that too! An FMF 4.1 exhaust rounds out the engine package and lightens up the KTM by over a pound, so there’s your bling. Sneaky mods that are a must have to me are a ZRT throttle that gives you a smoother overall feel and is much stronger than the plastic lock on system that KTM comes stock with. The ZRT is controlled via a bearing and that bearing gives you an unbelievable easier to use throttle even when your throttle cables get worn (which they will do around the 20-hour mark). These changes that I made make a huge difference and gets me excited to ride even when I am tired from a long week of testing. I don’t need all the bling with my bikes to get me excited, I just need a bike that performs out on the track and allows me to ride faster. I am more of a function over fashion type of rider with my machines and this KTM is now my type of vet racing 450. 

Top 5 Mods To The 2021 Suzuki RM-Z450

Just because the 2021 Suzuki RM-Z450 hasn’t changed doesn’t mean it still isn’t a viable option for a lot of riders out there. No, this isn’t the best bike off the showroom floor, but we put together what we feel is the TOP 5 MODS that will make the RM-Z450 a better motorcycle without completely draining your bank account.

Full Or Slip On Muffler System: The 2021 Suzuki RM-Z450 lacks a little bottom end pulling power, so in order to get a little more of that, the easiest thing to do is throw on a slip on or full muffler system. The PC slip on system didn't “wow” us for initial RPM response at first, but we installed the insert into the muffler and that helped back pressure enough to create some more throttle response. I liked the insert in for increased bottom to mid range throttle response without losing much top end pull. Installing this PC system helps with coming out of corners and also helps the Suzuki’s recovery time when in the wrong gear. With the stock system, the recovery time out of corners (if you were a gear too high) was embarrassing for a 450cc machine. It would be hard to get back into the meat of the power, forcing you to downshift and then immediately upshift, in order to get moving again quickly. With the PC slip on system the rider can fan the clutch lever a couple times (in the higher gear) and it helps get the Suzuki on down the track in a quicker manner. The PC system is a step in the right direction for bottom and mid range pull. It doesn’t help or negatively affect the top end at all. Yes, we would still like a little more to make us happy, but this is a mod that actually makes a difference. You can get a little more top end with the full system as the headpipe does help the top/over-rev of the yellow zook.

Ride Engineering Link: Simply installing the Ride Engineering link helped balance the RM-Z out on de-cel. If you’re running the stock suspension (valving/springs) this simple mod will help the RM-Z from wanting to transfer its weight towards the front end. The RM-Z450’s BFRC shock is known for unloading on de-cel (or riding high off throttle) and that can cause oversteer (knifing) on entrances of corners. Once you install the longer Ride Engineering link arms on the Suzuki it will settle down on de-cel and not pitch towards the front end as much. Running the sag at 107mm (fork height 4-5mm) with the link arm will alleviate some of your balance issues on the #RMaRMy. www.ride-engineering.com 

Vertex Hi Compression Piston Kit: Installing a 13.5:1 Vertex piston kit helped get some added excitement out of Suzuki’s bottom to mid range. Stock compression is 12.5:1 on the RM-Z450, but bumping the compression up to 13.5:1 allows for us to still run pump fuel safely. Where you will notice the added pull is on deeply tilled tracks or soft tracks that force the rider to get on the throttle harder. The Suzuki now feels a little “spunkier”, “livelier”, and “more fun” to ride. It also helps the chassis feel lighter when the track is tighter or when it gets rougher. It allows the rider to “pop” over bumps and makes the Suzuki feel a little more playful. For even better low end run this piston with VP T4 fuel or Renegade MX4. www.vertexpistons.com 

Hinson Clutch Kit (Basket, Pressure Plate, Inner, Fibers, Steels, Springs): The stock clutch fades quickly during motos and the clutch lever actuation (engagement) is very narrow. Once the Hinson clutch kit was installed the feel of the clutch was more positive and less vague. The Hinson also took the improved bottom end we got from the muffler/piston and transferred that power better to the rear wheel. The stock mushy lever feeling was gone and a slightly stiffer firm feel replaced it. However, it wasn’t a “Honda hard pull” feel, just a slightly firmer/more positive than the stock Suzuki pull. We have been riding with the Hinson clutch for over a few months now and that feeling hasn't changed one bit. We also have to change our clutch plates less as the Hinson set up doesn't get burned up as quickly. www.hinsonracing.com 

Optional Tuner Map: 

If you’re looking for a little more pulling power out of corners and more mid range meat from your 2021 RM-Z450, try the map out above on your MX Tuner App. This map works great with the PC system and some VP Racing T4 fuel..

Top 5 Reliability Mods To The 2021 KTM 450 XC-F

Written By: Gary Sutherlin

When you hear the phrase “Top 5 Mods” for a KTM most of the time you think of things like, exhaust, engine, ECU or maybe some cone valve forks. However, in this Top 5 Mods article I went outside the box a little since I’ve spent a few years riding this KTM model and have tried numerous exhaust, engine, ECU, and suspension mods already. KTM has marketed the new 2021 KTM 450 XC-F as a 50/50 motorcycle. Basically, KTM believes for the customer, this bike can be ridden on the motocross track Saturday and then trail riding with your buddies on Sunday. And it can…. almost (check out the air fork section at the end for more on that topic). Now, the mods that I’m going to share with you aren’t going to break the bank and set you back thousands of dollars, I mean geez, you just spent $12k on a new bike so the hell wants to do that?  With these mods, your ride will be massively more enjoyable, and your bike will last over the long haul.

1. GPR Pro RBM Kit V5 Top Clamp and Stabilizer: It still amazes me today that more people don’t utilize the great qualities of a good stabilizer. I worked with Randy at GPR about a year ago when he was designing the new V5 and asked about adding his elastomer set-up to help with bump absorption and feedback in the handlebars. That set-up is what went into the new Pro RBM Kit which provides the comfort and stability I’ve been looking for in the front end of the KTM. This kit was built for professional riders only and for the first time, is actually available to the public. This has always been one of the keys to my success and I’m happy the public can finally get them too. 

2. Rekluse Inner Clutch Dampeners: Breaking a rubber is never a good situation. But unfortunately, KTM is known for it, hence Husky and Gas Gas. The clutch rubbers in the KTM 450, in my experience, last around 4-8 hours depending on the way you ride. Once they diminish, you’ll need to replace the clutch pack as well, but instead of replacing the rubbers with the stock ones, I recommend using Rekluse. They have designed a clutch rubber that will go the distance.  I’ve put over 60 hours on one set in the past including a few 2-hour plus races. The stock clutch rubbers on the test bike made 8.7 hours before they started to crack, which led to some slipping. You may not feel a physical gain on the bike, but you will in your wallet.

3. Brake Tech Rear Caliper Piston: Replacing the piston on your new KTM 450 may be one of the best mods on the list but its not the piston you think. I’m super hard on rear brakes and have even melted the rear caliper itself. Brake Tech has redesigned this brake piston to hold 20cc more brake fluid in your rear system as well as drilled holes in the end to help distribute the heat better. Not only do I NOT experience brake fade on long trail rides or racing, but it stopped that annoying rear brake squeak and locking up of the rear wheel while entering corners. With less heat in the rear brake system, I now have increased pad life as well. Editors Note: Gary roaches brake pads in one race! Serious! If he says this works, I will be trying these for myself!

4. Zip-Ty Shark Fin: Zip-Ty Racings rear brake rotor shark fin has been a must have on my bikes for over a decade. Whether you are at the track or on the trail there is always that one rock that jumps up and bends your rotor. So before reaching into your toolbox for a crescent wrench to bend your rotor back or ordering one on Rocky Mountain ATV/MC save yourself the hassle and order one up. Zip-Ty also offers a variety of parts that coincide with the shark fin that make rear wheel changes easier and provide the protection needed for both off-road and motocross. 

5. Unbreakable Brake Pedal Tip by The Ride Shop: This product has a lifetime guarantee. If you can break it, he’ll replace it. That’s the motto Jonny from The Ride Shop had when he set out to build this pedal tip. Most brake pedals fold horizontally (or backwards) and don’t actually create more space. With this unbreakable design the pedal folds up vertically which allows you to hit objects at any angle and it will deflect. Putting pieces like this on any race or long-distance riding machine helps create a sense of calm as it’s one less thing you have to worry about having an issue. In my career, this is about the only part on a motorcycle I’ve never broken. 

What about the Air Fork?

The reason I say the KTM 450 XC-F falls short of a true 50/50 motorcycle is due to the air fork. While I believe for the average consumer the air fork has the features, they need to be successful, I don’t think it’s the case for a higher level rider. At my speed, the faster I go and the rougher the track gets, I cannot get the air fork to perform to match my performance. I spent a lot of time working with the air fork while I had this motorcycle to try to adapt to the different tracks and conditions. Unfortunately, I was never able to get it to be predictable enough for my speed/weight and that’s my only knock on the KTM’s suspension.

2021 KTM 450 SX-F Baseline Settings/Top Mods

The 2021 KTM 450 SX-F orange brigade is an amazing machine to ride! It only gets better with some modifications and some tweaks. The KTM 450 SX-F responds well to a few mods and with that makes for one hell of a fun motorcycle to ride/race. Here are few things that you can do to make your 2021 KTM 450 SX-F better. Do one or do them all, but just note that each mod makes enough difference on the track for my tired old ass to type about it when I get back to the office.   

Engine/ECU: For 2021 KTM has a better ECU setting and although it’s clean, I still would like some more added RPM response/puling power. I have been on the Vortex ignition bandwagon for a couple years with this machine and for 2021 it hasn't wavered. If you want the same great rear wheel connection as well as more pulling power everywhere, look into a Vortex ignition from Chad at XPR Motorsports or Jamie at Twisted Development. I have turned a lot of KTM riders onto this mod and have had a 100% approval ratio. What I like about this modification is that it doesn't hurt reliability and makes for a very usable yet powerful engine for almost every type of rider. Yes, it will set you back around $800.00, but to me is much better than slapping on a muffler system and will do more for your engine. A stock re-map will not get you nearly the rpm response or pulling power that a Vortex will give you. Another good reason to get a Vortex ECU is that they have great resale value. You will also most likely be able to keep that Vortex ECU in circulation (if you get a new 2022 KTM) until 2022.5 as that will most likely be the year that KTM will release it’s new model. 

Suspension: If you haven't listened to my WP XACT Pro Components suspension podcast you may want to at least check that out, but if you're sticking with the stock suspension for a while, you can try this setting to see if this helps comfort when the track gets rough. This setting below should be in the ballpark for riders around 165-200 pounds, but if you’re heavier than 200 pounds going to a stiffer rear spring will help the ride attitude of the KTM. I have went to several tracks and tried many different settings, but this specific setting had the most “track toughness”. The KTM’s stock WP suspension doesn't quite have the comfort like the Husqvarna does, but the KTM/WP set also holds up more in the stroke, which is a better fit for me personally. To get some added comfort back with the added hold up, try this setting. 

Fork (Stock Triple Clamp): 

Height: 5mm

Air Pressure: 11.0 Bars

Compression: 13-14 clicks out

Rebound: 15 clicks out

*With KTM Hard Parts Triple Clamps or Ride Engineering Split Clamps*

Height: 5mm

Air Pressure: 11.1 Bars

Compression: 15-16 clicks out

Rebound: 13 clicks out

Shock:

Sag: 104mm

Low Speed Compression: 10 clicks out

High Speed Compression: 1-1/2 

Rebound:  11 clicks out

WP XACT Or Spring Conversion:

This is a question I get a lot! Which is better? Should I get a spring conversion or XACT Pro Component fork? I have tried Enzo’s KYB conversion as well as a REP valved XACT fork and both have their advantages. The Enzo KYB conversion soaks up small bump/hard pack chatter better than a REP XACT fork, but the REP XACT fork moves less and to me has slightly better performance with slightly less comfort. Both spring set ups are better than other re-valved AER set ups that I have tried and to me the spring set ups are way more consistent throughout the day. You will have to decide on how much money you want to spend (Enzo KYB Spring Conversion is around $2000.00 and the XACT fork is around $3000.00) as well as what type of rider you are in order to get the most out of your suspension. If you like a fork that moves in the stroke a lot and follows the ground well (front tire contact patch), the KYB conversion is great. If you want the most hold up as well as a fork that allows the rider to charge/hammer through big bumps easier, the XACT fork set up is also a great choice.  

Chassis: Aftermarket engine mounts are all the rage right now and some of you may not have the money to spend on a pair of engine mounts for your KTM. I will say that I do feel like the KTM chassis is stiff when new, but be patient as it will break in and feel better after 15 hours or so. I decided to play around with torque specs on the engine mounts for fun and stumbled across some more comfort. If you’re experiencing a stiff feeling chassis sensation and want the KTM to settle while leaning (under throttle), there is an inexpensive way to achieve some extra front end traction (as well as an overall more planted feel). You can torque all top engine mount bolts to 30Nm. This band aid will give you a more planted sensation when on throttle while leaning the KTM 450SX-F through sweepers and fast straights. You will have to make sure that all engine mount bolts have blue Loctite to ensure they do not back out (you should do this regardless if you keep all the bolts in or not). You can also try torquing your swingarm pivot bolt to 95 Nm (instead of 100Nm) to help rear end traction out of corners. The downside to doing these mods is that the chassis will flex a little more, so if you’re riding deep tilled tracks this modification might have too much flex for some (especially when chopping throttle).  

Handlebars: The stock Neken handlebar is too stiff and doesn't offer too much comfort. Throw them in the trash. Get yourself a set of Pro Taper bars and make your arms and hands happy again. The Pro Taper SX Race bar worked well for riders from 5’8 to 6’1. The SX Race bend comes in a crossbar or crossbar-less style and is 800mm width, 87mm height, 54.5 rise, and 54mm sweep. If you’re looking for a better “stand up feel” from your KTM look for handlebar close to this measurement. If you do like the stock bar try the Pro Taper Husqvarna Stock bend with 5mm bar mount risers (Ride Engineering sells these).  

Triple Clamps: After riding back to back with the stock triple clamps, the KTM factory clamps and the Ride Engineering clamps I have realized that the stock clamps are stiffer. I have since installed the Ride Engineering triple clamps on our 2021 KTM 450 SX-F with excellent results. The front end has more of a softer initial touch on slap downs and the fork action is smoother on de-cel bumps. It’s crazy to think that the fork feels softer now with the Ride clamps installed, but that is exactly how it feels when riding on the track. I was able to increase my air setting on my fork to help hold up off-throttle and kept more comfort through the entire stroke (with the stock AER fork). I also get slightly more lean angle front end traction (or cornering stability) with the Ride clamp because the front end isn't bouncing around inside long/choppy ruts. The KTM factory clamps are close in comfort to the Ride clamps, but offer slightly less straight line front tire feel.  

Rear Brake Pedal Spring: Purchase a Honda CRF450R rear brake pedal spring with the rubber around the spring. The KTM rear brake pedal spring vibrates and will break every 3-4 engine hours. Orrrrrrrrr. Get a Fasst Co rear brake return spring and be done with it! Fasst Co’s rear brake return spring offers tunable pedal resistance and a more controllable feel by placing the spring in compression instead of tension, minimizing the "on-off" feel of most rear brakes. 

Gearing: I like the stock 13/49 gearing for most conditions. If you remember last year I thought 14/52 was better in sandier conditions, but have come to the realization that I liked the gear spacing more with the 13/49 gearing. 

Twisted Development Exhaust Flanges:

The Twisted Development exhaust flanges are shaped differently than the stock OEM flange, which can change the engine character of the KTM 450 SX-F. I went through several during testing and found out a size/shape that can actually enhance the low to mid range power character. Compared to the stock piece the TD Performance flange will give you better throttle response through area 2-3 (mid to exit) of corners. Another advantage to me is that the TD flange helps pulling power out of corners as well and helps third gear lugability. The TD flange just helps the RPM’s pick up quicker, which in turn makes the KTM feel lighter when the track gets bumpy. There is no need to remap your ECU and it takes minutes to install.  

 The TD flange works with the stock headpipe/muffler system or any aftermarket system. I tried it on a stock muffler system as well as a full FMF system and with both, the TD flange helped in aforementioned areas. For $200.00 bucks, to me, it’s a great way to get a little more snap out of your KTM 450 SX-F. 

Rear Axle/Axle Blocks: Going to a Works Connection Elite axle block kit or Ride Engineering axle block kit will get rid of the fixed left axle block on the stock KTM’s axle. This will help the rear end to move more freely under throttle and improve the shock’s comfort on acceleration chop. Both are great, but you will have to decide if you want a complete axle/axle block kit like Ride Engineering’s  or just the blocks themselves like WC’s.

Muffler: To me, FMF makes the best muffler system for the KTM 450 SX-F. There are some other companies that have other bikes dialed in more, but on the KTM, FMF has got it down. You will get more low to mid RPM response as well as more mid range pulling power. Top end is increased plus the over-rev is as good as stock. It is one of the few times that I was impressed because it was actually better than stock in almost all areas. The downside is that you must keep up on muffler packing (every 10-12 engine hours) because the FMF will blow out and that could damage your expensive titanium can. Did I mention that you will lose almost two pounds with this system? If you slap on spring forks you will be gaining almost three pounds. You can get most of that back with a 4.1 Titanium FMF Muffler system.

If you have any questions about any of these settings or mods please contact me at kris@keeferinctesting.com and I am happy to help you.

2021 Yamaha YZ450F Baseline Settings/Mods

The 2020 and 2021 Yamaha YZ450F’s are identical minus some different graphics, so this gave me a chance to experiment more with standard settings as well as other aftermarket mods for this machine. For a bike that may get some flak thrown its way in the professional motocross racing world, this Yamaha YZ450F machine has treated me exceptionally well this year in my racing endeavors. I have won a Loretta Lynn’s title as well as a Vet World Championship on the exact same machine and haven’t had a huge maintenance list to go through.

Is the Yamaha YZ450F the lightest bike? No. Does it corner the best? No. Does it have the best cockpit? No. To me, when I answer those questions with a “no”, it doesn’t necessarily mean it’s bad. I don’t want a twitchy machine that has tons of cornering strength anyway. When you have a bike that can corner excellent, chances are high that you will have some stability issues. The Yamaha is a great middle of the road machine that does everything good. Below are some key settings, as well as mods, that I have rolled over into my 2021 YZ450F. These can help you drop your lap times, give you more comfort on the track and make a good bike, GREAT! 

Suspension: If you’re sticking with stock valving the 2021 Yamaha YZ450F’s suspension settings are still slightly soft (once suspension is broke in) at times on bigger bumps at speed. Going slower on the action as well as stiffening the compression really helps the whole bike remain planted around the track. The comfort that the KYB SSS fork/suspension has is unmatched and the track toughness it provides makes your life so much less stressful on set up. This setting below will work for most riders ranging from 165-195 pounds with no gear. 

Fork: 

Height: 5mm

Compression: 6-7 clicks out

Rebound: 7-8 clicks out

Shock: 

Sag: 104mm

Low Speed Compression: 8 clicks out

High Speed Compression: 3/4 turns out

Rebound: 7-8 clicks out 

Engine/Power Tuner App: I have tried several maps on the YZ450F, but have always came back to the two below. The stock engine has a lot of bark (rpm response) from 0-10% throttle opening and for the tracks that we have out here (on the west coast) it’s too much at times. For you east coast riders try the “TP5” map as that should be enough bottom to mid range delivery to get you out of that soft soil, yet keep it manageable/linear to hold onto for a 20 minute moto (YES, I AM JEALOUS OF YOUR DIRT!). For all the rest of you, try the TP 3.0 map as that is the map that I use 80% of the time. The linear/easy to roll on throttle delivery along with the longer pulling power that this map has makes it a tractor around the track. This makes connection to the rear wheel much more apparent with this TP version. Yes, these maps will also work on your 2019 YZ450F, so give them a try.…  

Seat: If there is one problem area of the Yamaha it is the seat. The seat still breaks down quickly and can feel clapped out. This makes you feel like you're riding in the Yamaha and not on top. I would say go get a taller GYTR seat, but for some reason, they don’t have any at this time! Come on GYTR, get it together! Since the tall GYTR seat is scarce at the moment, I am sticking with a standard height/density GUTS foam which is actually a little firmer than the OEM foam. If you still can’t find the GYTR tall seat then go to gutsracing.com and get yourself a standard foam.

MX3S or Pirelli MX32 Mid-Soft Front Tire: Yamaha will not want to hear this, but I feel the Yamaha corners better with a Dunlop MX3S/Pirelli MX32 Mid-Soft front tire rather than the stock MX33. If you’re having trouble with initial lean into corners, get yourself a Dunlop MX3S or Pirelli MX32 Mid-Soft front and thank me later. 

Gearing: I tried a 13/50 gearing set up for all you novice riders, but it didn't work as good as the stock 13/49 set up. The stock gearing is just fine for 90% of tracks because the Yamaha’s engine has so much torque that it can pull third gear. Yes, even for you novice riders! Third gear is that “lugable” that you will not stall through corners, just make sure to cover the clutch lever. 

Triple Clamps/Offset: The Yamaha YZ450F doesn't need aftermarket triple clamps nor does it need an offset change. The rigidity balance that the stock clamp has is a blend of comfort and performance that is hard to find with aftermarket clamps. Still having a hard time in corners? Don’t purchase clamps, simply go to a 102mm shock sag setting or go to a fork height of 7mm. I suggest trying one or the other, not both at the same time. This keeps balance as well as keep the superb bump absorption of the chassis/clamps. Some other machines accept aftermarket clamps better than others, but this Yamaha has the most comfort/performance with the stock clamp. Don’t go backwards on your set up by purchasing parts you don’t need!

Muffler: I go back and forth between the Pro Circuit and FMF muffler systems if I am not running the stock muffler. Both systems are smoother off the bottom end and pull more in the mid range than the stocker. I like this because it can actually calm the chassis down a little on acceleration bumps. There is nothing wrong with the stock system, but if you MUST get an aftermarket system go with one of these two brands. 

Enzo Re-Valved Suspension: If there is anyone that knows KYB suspension it’s Ross from Enzo Racing. Ross has been doing my Yamaha bump sticks for years and even though I can be a pain in the ass, the guys at Enzo always seem to find a setting that makes me happy. What exactly did I want to improve upon from the stock stuff? I loved that the stock suspension had tons of comfort in the small bump category, but I needed a little more hold up from the stock suspension when pushing it harder over bigger braking bumps. The fork has a tendency to dive a little when off throttle and that can upset the shock leading into area one of the corner. The Enzo guys improved upon the fork by adding more hold up with the valving, but not going so stiff that the Yamaha gave me deflection on braking bumps. Enzo also incorporated their spring tubes. When I tested back to back with the Enzo spring tubes as well as the stock spring tubes the Enzo setting gave me a little firmer feel through the mid stroke and allowed the bike to be more balanced off throttle (less diving). My fork is still relatively soft in terms of a setting, but it makes for more front end feel through corners and that is key for me because I am a front end steering rider. The shock was also firmed up so that the rear of the YZ450F didn’t squat too much under acceleration. An Enzo high speed adjuster was installed on the shock and that can be felt under heavy loads such as g-outs and jump faces. The Enzo adjuster is slightly different internally (the Enzo guys can explain it better to you then I can) than the stock adjuster, but on the track the rear of the bike tracked straighter under acceleration as well as kept a firmer feel to the end stroke. I kept the stock spring rate in tact on both ends of the bike, but only beefed up the valving in order to achieve a well balanced YZ450 on or off throttle.  

Vortex ECU: I haven’t been that vocal about this mod because it’s so hard to justify spending $800 bucks on an ignition when the Yamaha ECU/Power Tuner app is so good. However after working on a ton of settings on the standard ECU, I decided to try the Vortex to see if I could make the power broader with it versus the stock piece. I have worked on settings with Chad from XPR  and I can say that we have spent many days with at the track trying to make the Yamaha not spool up so quick (light crank feel). You might be asking yourself, “what the hell is spool up”? The Yamaha has a quick revving light crank feel and sometimes that feeling can cause lack of rear end traction when exiting corners. Now this is great when traction is high and the dirt is deep, but once the track gets rough, this Yamaha can be too much to handle compared to a KTM or Husqvarna. Adjusting the ECU via Power Tuner App helps a little, but for safety reasons Yamaha only allows certain parameters, but the Vortex ECU has a wider range of adjustment. Adding the Vortex ECU helps lessen engine braking and also gives the Yamaha a longer power character. Now usually when you get less engine braking in any particular engine character you might feel a more free feeling engine, but with the mapping that Chad created, it makes the power more controllable with less pitching off throttle. The maps that we came up with help rear wheel traction out of corners, allows the rider to ride in third gear even easier, yet allows me to use second gear longer out of corners. Once I got a map (with the Vortex) that wasn’t too powerful, I have noticed an improvement in chassis feel when the track gets rough. The YZ450F can be pushed harder through bumpy conditions now that the delivery of the Yamaha is much broader with less engine braking. I used XPR’s mapping in the Vortex ECU at Loretta Lynn’s and World Vets as I felt more connection to the rear wheel with Chad’s map at the end of the day. I would recommend anyone looking to get more connection as well as more power to get with Chad and ask for the Keefer National & World champion map.

2021 Honda CRF450R Initial Baseline Settings/Mods

I have come to find out that Honda didn’t allocate enough 2021 Honda CRF450R’s to dealerships, so if you’re lucky enough to be able to get your hands on one, you may be looking for a couple fixes and a baseline settings for your new red ride! Have no fear as I have been spending some quality time on the 2021 Honda CRF450R and have come up with a couple fixes as well as a setting that may work for a broad range of riders. Below are a couple mods that you can do for a relatively low cost and get a dramatic change in the way your 2021 CRF450R rides. 

ECU Setting: 

Honda doesn’t exactly want you to change their ECU settings, but in the 2021’s case, we have no choice but to try and get some better maps as the standard 1&2 maps are very rich/dirty feeling on low RPM situations. Honda doesn’t “really” have an ECU tool for the consumer to make custom maps, so we have to leave it up to only a chosen few techs that have the Honda’s programmer. Even when a tech has a Honda programmer, map 1 is locked, so only map 2 and 3 are available to change. I have talked to a few 21’ CRF450R owners that DO NOT feel the rich/dirty feeling, but if you find it bothersome, I have tested some new maps with Jamie from Twisted Development that will help. You can send your stock ECU into Twisted Development for a re-flash that will change your map 2 & 3 settings. With the Twisted re-flash, map 2 now has better pulling power than the standard map two, but still feels long and linear like map 1. Connection is better to the rear wheel now that map two is cleaned up so slow RPM cornering is much cleaner. Acceleration out of corners provides more forward rear wheel bite and helps second gear roll on delivery. The Twisted #3 map has more bottom end snap and pulls harder out of corners, which is great for softer conditions. This map is great for you eat coast soft/loamy riders, but still fairly manageable when the track gets rough. With the Twisted re-flash the 3rd map gives you more bottom mid range with a little less over-rev, so this map is a great third gear roll on map for lazier riders. The Twisted re-flash will set you back $200.00 and is well worth the money considering how bad the standard mapping is on the 2021 Honda CRF450R.  www.td-racing.com or 951-698-7222

Optional Suspension Setting: 

The stock suspension might be too soft for you if you’re anywhere over 180 pounds. Honda has a 5.0 N/m fork spring that is adequate for most, but the valving seems too soft. Out back the 54 N/m shock spring is also way too soft, so if you’re looking for a quick band aid to make your Honda CRF450R better, without going to a re-valve, going a spring rate up on each end has helped me feel more secure on high speed tracks, as well as soft bumpy tracks. Bringing both ends up a little in the stroke (with the heavier spring rates) has given me more front/rear wheel traction as well a Honda that corners better without over-steering. Unlike the 2020 Honda CRF450R going up a spring rate on the 2021 version has given the new red bike more track toughness. If you’re not into spending more money on a re-valve at this time, simply get some heavier springs and try this setting: 

Fork: 

Spring Rate: 5.1 N/m

Height: 2mm

Comp: 11-12 out

Rebound: 11 out

Shock:

Spring Rate: 56 N/m 

L/S Comp: 12 clicks out

H/S Comp: 2 3/4 clicks out

Rebound: 10 clicks out

Sag: 106mm

Test Muffler Shown. Not production model.

FMF 4.1 Muffler System: 

Putting an aftermarket muffler system on isn’t necessarily about more horsepower, but about changing the character of the engine in a way that the Honda needs. I went out and tested three different versions of what FMF is about to offer the consumer and the one I chose looks to be the one that will go into production. So what does the 4.1 system do? What I liked about the 4.1 system right off the bat is that it calmed down the vibration feel that I get on the Honda. For whatever reason bolting on the 4.1 helped the harmonic vibration that I get when hitting higher RPM’s from the stock muffler. This actually gave the Honda more comfort, because it felt less rigid! The 4.1 also made the engine character broader with better low end RPM response, but with a smoother roll on. Mid range is increased as well as slightly more top end/over-rev in 2nd/3rd gears. After going through three different versions of pre-production FMF systems and several headpipe/muffler combinations I was pleased with what we left the track with. I was so pleased that I kept my favorite FMF combination on my test machine. 

2021 Kawasaki KX450 First Phase Mods

We have documented a lot of evaluations to the 2020 Kawasaki KX450 right here on Keefer Inc., but I haven’t personally been a part of some of those tests. At times I am simply too busy on other projects, but for 2021 I am going to be personally doing some mods to the 2021 KX450 that I think it needs. Last year my test rider Joe Oehlhof did a ton of work to our 2020 test bike and when I did get to try those mods, I was always impressed with what Joe did to the green machine. Kawasaki didn’t do much to the 2021 model, but the change that Kawasaki did make that I thought was huge was the new clutch. The new cone disk spring clutch makes the Kawasaki more connected to the rear wheel and has less slip under load. The Kawasaki KX450 has the most stability in the 450 class and allows me to hit braking bumps harder because of the very comfortable frame character. The KX450 frame has a slower reactive nature, but this is a very good feeling when the track gets hammered. When hitting bumps at speed, the frame has so much absorption that the suspension setting is less crucial than other 450 machines that are out there on the market. Overall, this is just a friendly machine to ride and the track toughness of the KX450 is superb.  

So after my first couple rides, I wanted to do a few mods that I felt were necessary, in order of importance. I already have installed 5.1 N/mm fork springs in order to create less pitching, but to me the engine needs a little more pulling power. The YZ450F has an incredible power plant, but can be a handful to ride when pushing hard. The Kawasaki KX450 has a smoother power character, but needs more Yamaha-like power in the mid range. This is how I described what I wanted when I spoke with Jamie from Twisted Development. He told me he thought he could get some more power with a Vortex ECU, but I had to decide on which muffler I wanted to go with first. 

After testing a couple mufflers I decided to go with a FMF 4.1 full system with their “SX” style headpipe. Now why did I choose the FMF system? To me the FMF gave me slightly more power where I felt like the KX450 needed it. The stock power curve of the 2021 KX450 engine has a snappy throttle response from 0-10% throttle opening and at times can almost be too touchy through corners (area 2) with the standard green coupler installed. Once rolling on the throttle and passed the corner, the power is not quite as strong as the Honda or Yamaha, but still has that rear connection that I really enjoy. I didn't necessarily need more bottom rpm response with the 2021 KX450, but I would be lying if I said I couldn't use more bottom and mid range pulling power when coming out of corners. What is odd is I usually want a little less pulling power from other 450’s, but in this case, I would like the green machine to have a little longer pulling power in second gear. The SX style headpipe, along with the 4.1 RCT muffler made the KX450 feel more playful coming out of corners and gave me slightly more mid range RPM response. The low end RPM response (0-15% throttle opening) was slightly less than stock with the FMF system/SX style headpipe, but now the KX450 had slightly more mid range pulling power without sacrificing too much low end snap. You do get slightly less pulling power on top end/length with the 4.1 muffler/SX style headpipe, but to me it was a minimal loss. Even though the stock Kawasaki muffler looks like complete dog doody, it actually performs really well on the track. To get an aftermarket muffler to perform better than a stock muffler is asking a lot these days, so being able to feel the gains I felt on the track with the FMF system was a selling point for me. 

Now that I got my system figured out Jamie from Twisted Development installed a Vortex ECU that we mapped to the FMF 4.1 system. You might be sick of me talking or testing with Vortex ECU’s, but to me, when mapped correctly, is one of the best bolt on mods that you can make to any new generation four stroke. The Vortex has such wide parameters that tuners like Jamie can really change the power character of an engine, without almost any reliability loss. With that being said I didn’t want to alter the Kawasaki KX450’s easy to ride engine too much, but I just needed more meat/pulling power in second and third gear. When I ride deeply tilled conditions, the Kawasaki needs more torque feel to get me on top of the dirt more. 

The beauty of installing this Vortex ECU is that it is super easy to bolt on and after you do, you can actually feel where your money went. That is tough to do these days when adding parts to your new motocross machine. Jamie listened to what I wanted and mapped the Vortex so that the KX450 now had more pulling power out of the corners as well as increased the length in which I could use second and third gears more efficiently. I can now roll out of corners in second gear, roll the throttle on and get more acceleration, but keep the rear wheel connectivity that I loved so much on the stock KX450 setting. The throttle control was still there in area 2 and 3 of each corner and when exiting I didn’t have to shift to third as quick like I did with the stock ECU. With the stock ECU (as well as a re-flashed standard ECU), I still couldn’t get rid of that flat power feel when making my shift from second to third gear. Twisted Development’s Vortex ECU setting allowed for more third gear recovery as well as gave the KX450 continued pulling power when making the shift to third gear in deep soil. I will say that adding this ECU doesn’t make the Kawasaki a third gear lugging beauty through corners, like the Yamaha, but at least now second gear is much more useable. 

We also mapped the Vortex to where the KX450 now had less engine braking coming into corners which gave the fork a more relaxed feel and that gave me better balance leading into area 1 of tight corners. When you affect any engine’s power character you also affect the way suspension can react and with this map it just increased the comfort of the Kawasaki’s chassis. Does the Kawasaki KX450 feel with these mods feel as fast as a stock YZ450F or CRF450R? No, it does not, but the ride ability of the Kawasaki is much greater than the other two machines mentioned. The rear wheel connectivity is better than the blue or red bikes and now the KX450 has an even lighter feel to it when I need to make sudden line choice changes mid corner. 

These improvements that I made to the 2021 KX450 is something I could go race locally with and be extremely happy. The FMF muffler system will set you back $950.00 and a Vortex mapped by Twisted Development is around the same. Without busting into your top end with cams, pistons and head work these two mods are the most bang for your buck when looking to actually feel a difference on the track. 

I am going to work on a couple suspension mods next, in order to get a little more performance out of the Showa bump sticks, so be on the look out for that test next. After we get a suspension setting that offers a little more hold up, I am going to ride the crap out of the KX450, so we can answer some of these reliability questions that some of you email me with. The 2020 KX450 proved to be fairly reliable for Joe, as he put just under 50 hours on it, but this year I am hoping to double that mark on the 2021 unit. 

Baseline Suspension Settings:

Spring rate: 5.1 N/mm (5.0 N/mm for light riders under 160 pounds)
Compression: 11 clicks out
Rebound: 10 clicks out
Fork-leg height: 2mm up

Spring rate: 54 N/mm
Hi-compression: 1-1/8 turns out
Lo-compression: 15-16 clicks out
Rebound: 10-11 clicks out
Race sag: 105mm

If you have any questions about these mods or anything to do with the 2021 Kawasaki KX450, please feel free to email me at kris@keeferinctesting.com and I am here to help! 

If you’re looking to get a FMF Racing 4.1 system like the one you see here you can click on the RMATVMC banner on my site and order through that or go to fmfracing.com. 

You can also call Twisted Development directly at 951 698 7222 or visit them at td-racing.com. 

2020 Suzuki RM-Z 250 Blue Collar Project Part three

By: Colton Aeck

As you all might know I was assigned the 2020 RM-Z 250 and started the project of finding some horsepower as well as handling improvements on a small budget. If you haven’t checked out the first two parts of this article, go back and give them a read for a more in depth look on what we’ve done so far. For a quick recap, here is what we got so far: with the help of an FMF 4.1 muffler, a Rekluse clutch, a NoToil air filter kit and a couple mods to the airbox, we were able to find some hidden power on the RM-Z. Race Tech also stepped in and got the suspension more comfortable than stock so I was able to actually push hard late into motos. 

While we had already made a big improvement to the RM-Z power plant, I still wanted more. We’d done just about everything we could without opening up the money wagon to the engine so in order to get some more horsepower as well as save some money, our next move was to send the head off to Race Tech’s engine department. Andrew at Race Tech did a five angle valve job and custom porting to the head. He also gave us a custom mapped Vortex ECU to match the head work they performed. This is something that is relatively easy to do yet can make dramatic differences on the track.

After I tested this machine for a few days I went and asked Andrew a few questions about the mods. He said that on the dyno, the numbers reported a 10% Horsepower increase through the midrange and top end. Dyno’s are not the end all be all of on track facts, but for this test I did have to agree with what the dyno had to say. In stock form the RM-Z makes decent bottom end, but doesn’t do anything exciting when exiting the corner. It has a mid range that feels flat and lacks pulling power on top. In other words I can’t let it rev out too far. I have to short shift, but when I do that the Suzuki still doesn’t have enough recovery to get back into the meat of the power. Race Tech’s head helped the Suzuki right where it needed it and made the spread of power broader and easier to ride. I didn’t notice any increase in bottom end, but I didn’t notice a loss either, which was acceptable to me. 

The total cost of the head work and ECU comes in right around $1500, which isn’t a whole hell of a lot, when you’re looking at what you’re getting on the track. That’s only a little more than you’d spend on a full system exhaust, but in comparison I think you get more bang for your buck with the head/ECU work. A pipe can usually improve on the stock engine character, but in this case I feel the head work actually changed the engine character for the better. Being able to use second gear longer through corners helped make this an even more fun yellow bike to shred ruts with. Third gear is still not an option on tight corners, but now that second gear is longer, I am not worried about pulling third so early. I used the stock gearing, but am looking to possible go up a tooth in the rear to see what it can offer me in third gear exiting corners. With the head work and Vortex ECU the Suzuki pulls down each straight farther and has slightly more recovery when I make that mistake. I like that the Race Tech mods gave me the sensation of a more playful yellow zook while keeping the reliability of this machine in tact. Yes, the Suzuki is reliable! I have been riding/racing the crap out of this bike and have experienced zero issues with it. After racing long/fast GP style courses as well as the tight ruttier technical mx tracks, the Suzuki has been easy to work on in the garage. 

After we got the motor sorted out, I made a few mods just for personal preference. I’ve been a Renthal guy all my life, but since testing with Keefer, I’ve really begun to like Pro Taper’s SX Race handlebar, so that’s what I chose for the RM-Z. They also sent me their “Twister” throttle tube, which is an aluminum tube with a bearing on the end of it. I honestly thought it was a bit of a gimmick, but I fell in love with how smooth and easy it makes the throttle pull. I’ll be running those on all my personal bikes from here out! The stock seat cover looks grippy, but I found myself sliding around quite a bit under acceleration. Motoseat fixed that problem with a ribbed gripper seat, yet it wasn’t so aggressive where it hurt my rear end after a long day in the saddle. 

My personal favorite tire combo is the Hoosier 25S front and 25 rear, so that’s what I chose for the RMZ. I like this combo because the tires have a great carcass feel an have excellent lean angle traction for me. Hoosier has a reinforced sidewall with the “S” models, so if you’re looking for a bit of a longer life span, look at the 25 “S” Hoosiers. Finally Elusive Graphics made it look pretty with a custom set of Keefer Inc Testing graphics. 

So now the big question. With the work we did, is the RMZ 250 competitive with the other bikes in its class? Yes and no. Does it have have the bottom end torque of a Yamaha? 

It still DOES NOT! Does it have the pulling power and over-rev of a KTM or Husky? No. 

The RMZ engine isn’t the best in any category, but with the work that we performed to it, it still can be respectable racing machine without the pricing of the other five manufacturer models. 

Where the Suzuki really shines is in handling. It corners as good or better than any bike on the track and it remains predictable and stable at speed after some suspension work. Simply put, it’s easy and fun for me to ride. I still ride at a high level and I would take this bike to race (with these mods) any day. 

So who is the RMZ 250 best for? 

I think it is best suited for a younger rider moving up to big bikes, a novice without a lot of experience or just your average guy who wants a great handling 250F that’s super fun to ride without breaking the bank. 

For the serious racer in the 250 class, horsepower is a massive part of the right? Simply put the RM-Z is down on power compared to its competition. Unless you have a big budget for engine mods, you’ll be fighting an uphill battle, but Race Tech helps soften that blow with a reliable head mod that makes more power. 

Suzuki has the handling/ chassis figured out. All they need is a faster engine and I think they could be in the running to win shootouts. Only time will tell if Suzuki has the budget to figure that part out, but just know there are modifications to the head that Race Tech offers you RMaRMy members without breaking the bank!

Bonus Tip:

If you own an 2019-2020 RM-Z 250 and you experience some chassis stiffness, think about giving this a try. 

I drilled a 4mm hole in the center of the upper engine mounts (in the middle). On the track it will give you a slightly softer feel through small chop as well as hard slap down landings. What I didn’t expect though, was increased front end bite on initial lean while turning. 

It’s a subtle change, but definitely something you all should feel. On hard packed So Cal tracks, it was a welcomed improvement. 

Stay tuned to the Keefer Tested podcast in the coming weeks where Kris and I will sit down for a little wrap up on my experiences with the 2020 RM-Z 250. 

2020 Suzuki RM-Z250 Tips/Tricks Part #1

Written By: Colton Aeck

Greetings, I’m Colton Aeck. You may recognize my name from slugging it out as a privateer at your local Supercross or Outdoor National. If not, I’m 24 years old, a professional racer and working on being a half decent test rider too.

While practicing in between Supercross races in January I had a mechanical failure that resulted in a bike crash. I broke several vertebrae, a few ribs and punctured a lung, but most important it got me thinking about my situation. Is busting my ass every week, traveling every weekend, risking major injury and sacrificing time and relationships with loved ones all worth it? For what? To come out profiting a few hundred bucks a week? It’s certainly used to be, after all I’ve worked my whole life to get this far, but getting injured sucks and maybe it’s just time to go back to why I started this all in the first place. Because I love to ride!

Cut to now, a few months later. I’m healed up and getting the itch to ride again. I have tons of great memories racing 2 strokes growing up. One day I stumbled on a super clean 2004 KX250 and thought “Perfect, this will be the most fun I’ve had in years!” WRONG... I love two-strokes as much as the next crazed pre mixed guy, but let’s be real, compared to today’s four-stroke machines they are slow and poorly suspended. I should’ve know better buying a 16 year old bike! 

Since I was regretting my two-stroke purchase I called up Keefer to see if he had anything I could ride. His 2020 RM-Z 250 needed someone with a purpose and it seemed like I needed one at this time, so I found a home for the yellow zook. To be frank, the 2020 RM-Z 250 gets a bad rep (and rightfully so in some cases). It’s down on power compared to its competition and in the 250 class, power is almost everything.

My first impression of the Suzuki is that it has good throttle response and bottom end pull, but once you really start riding harder it feels choked up, like it’s starving for air. There just isn’t a whole hell of a lot of pulling power after I gt out of the corner. After taking the seat off I knew the first mod I wanted to make was to try and open up the airbox. On the inside of the number plates there is a triangle shaped snorkel piece that sticks into the airbox. Using a heat gun or a torch, lightly heat up the plastic to soften it a bit (don’t melt it!) and take a sharp razor knife and cut the snorkels off flush with the inside of the plates. 

I recommend doing this at the track, in between motos so that you can feel the difference, but if you can’t doing it at home will be justified on the track, trust me. Just taking the bike off the stand and starting it, I already noticed improved throttle response and a quicker/freer revving engine character. On the track you will feel improved power across the RPM range. Coming out of corners the bike pulled longer and gave me a slightly more exciting feeling. 

While I had the side plates off I noticed the stock airbox seems very closed off. Almost like something you’d see on a trail bike.Once again, with a heat gun and a razor knife and a little patience I opened the airbox up a ton. I cut around the outside edges along the subframe and the front edge where the number plate attaches. Make sure to leave enough plastic on the front edge so the tabs on the number plate still have somewhere to lock into. On the track I noticed another significant improvement to throttle response and it overall an improvement in pulling power across the whole rpm range. This Suzuki is starting to wake up a little and I have yet to spend any money! Winning! With almost any kind of mods you’ll have some downsides. Opening up the airbox is a big improvement on the track, but you will notice your bike is a bit louder (more intake noise) and your air filter will get dirtier a little sooner on sandier tracks. Unless you’re lining up at a Supercross, sound is probably not an issue for you so I didn’t work about it.

The next obvious choice for me to make that did cost me a little was to install a FMF Factory 4.1 full system. The FMF is much lighter than the stocker and improved bottom to mid pulling power. I didn’t notice any major improvements in top end/over-rev, but the FMF was another step in the right direction towards getting some more meat inside the the RM-Z250’s engine. 

With only these two mods the RM-Z250 makes me smile a lot more than when I picked it up from Keefer. Stay tuned for more tips/tricks and mods as I dive into the suspension as well as inside the motor on the next installment of project yellow zook. If you have any questions about the Suzuki RM-Z250 you can email Kris at kris@keeferinctesting.com and he will make sure to pass it on to me. 

Top 5 Mods To The 2020 KTM 125SX

My 14 year old son has been riding the 2020 KTM 125SX off and on for over six months now and although he likes the bike, he has struggled with set up from time to time at different tracks. He and I have worked on some different settings as well as added a few mods that has kept us happy at several tracks in Southern California. Yes, that’s right we do share the bike and some track days. Most of these mods are inexpensive and can make your orange screaming pumpkin a little more comfortable as well as make some extra ponies. Here are five mods in no particular order that we thought were worth mentioning. 

Ride Engineering Link:

For this test I had two KTM 125SX machines. One was set up for my son, with his softer shock spring and one was just a bone stock KTM 125SX with the sag set for me at 105mm. We started later in the day at a couple tracks on separate days to make sure the track was nice and broke in before we started to make our changes. Doing this ensures that the track doesn't change too much from each change we made to the orange machines. With the Ride Engineering link I noticed better tracking/acceleration coming out of choppy corners and slightly more stability off-throttle. I really liked that the link helped the ride attitude of the KTM when leaning, under throttle, on choppy terrain. I had more trust in the KTM when loading the chassis hard on throttle. I didn't get near as much kicking coming down rough hills and the overall cornering character didn’t suffer. I was worried that this Ride Engineering link would hurt turn in, but to my surprise it didn't affect the KTM’s easy natured turn in character. 

Aden’s comments didn't exactly mimic mine, but one comment that actually made sense was he did like that he felt lower to the ground, when sitting, and that helped him with his starts. When watching him ride the bike was visibly less busy in the rear and didn't give him as much kicking on de-cel. The length of the Ride Engineering pull rods are 1.3mm’s longer than stock and come in at a 149.5mm overall length. Aden doesn't know enough about chassis testing to give me some great feedback, but some of his comments overlapped mine. I more or less watch the bike when he rides and then decide if it’s a good direction or not. We decided to leave the Ride Engineering link on his bike after we both came to an agreement that he looked/felt better on a rough track with it on.

If you do decide to get the Ride Engineering Performance Link just know that you may have to adjust your AER fork pressure, if you’re still on air forks. Now with the Ride Engineering pull rods installed the rear end will ride a little lower, so the front end might seem a little high. Dropping the air pressure anywhere between .2-.5 bar might be needed to get some added front end traction. We dropped Aden’s air pressure from 8.3 bar to 8.1 bar at some tracks and even down to 8 bar at others. Try running your normal AER pressure when you first put on the Ride pull rods and see how your front end feels though corners. If you feel like your front end is tall, your front end is pushing, or have a vague front end feel, just try to drop your air pressure slightly. This will help let the fork use more of its stroke and get that front tire to bite into the ground more. 

Jetting:

Jetting was pretty close in stock form, but we noticed if we ran VP C12 or T2 it does become a little finicky (rich) off the bottom. Here are the jetting specs for pump fuel and VP T2 racing fuel. 

Pump Fuel:

Main Jet: 500

Pilot Jet: 35

Needle: 6BFY43-71

Clip: 2nd position

Air Screw: 1 out

VP T2 Setting:

Main Jet: 520

Pilot Jet: 32

Needle: 6BFY43-71

Clip: 2nd position

Air Screw: 1.5 out

Suspension Settings:

120-140 pounds:

FORK:

Air: 8.1 bar
Compression: 10 clicks out

Rebound: 10 clicks out

Fork-leg height: Stock

SHOCK:

Spring rate with or without link arm: 36 N/m (39 N/m is stock) 

Race sag: 104mm
Hi-compression: 2 turns out

Lo-compression: 16 turns out

Rebound: 13 turns out

150-170 pounds:

FORK:

Air: 8.4 bar
Compression: 14 clicks out

Rebound: 11 clicks out

Fork-leg height: Stock

SHOCK:

Spring rate with or without link arm: 39 N/m

Race sag: 105 mm
Hi-compression: 1.5 turns out

Lo-compression: 13 turns out

Rebound: 11 turns out

FMF Factory Fatty Pipe/Shorty Silencer:

I went back and forth with the stock set up as well as the FMF a couple times at a few different tracks and I will say that the FMF Factory Fatty pipe/Shorty silencer combo did help throttle response as well as low end grunt. Coming out of corners (with the FMF Fatty/Shorty) the KTM 125 SX has a little more acceleration pull on corner exits and could be shifted a little earlier without falling off. The mid range pull was also longer and overall crispness of the mid range seemed improved. The FMF Fatty/Shorty seemed to slightly lean out the bottom to mid range (in a good way) and made the KTM feel more playful around the track. RPM response was improved throughout the power and the throttle felt more connected to the rear wheel. The top end pulling power/over-rev was slightly shorter than the stock set up so going to the jetting above helped get some of this back.

VP T2 Racing Fuel: 

T2 is a 40:1 pre-mixed racing fuel that increases bottom to mid range response over pump fuel. I performed a couple blind tests with Aden on a couple occasions and each time I poured in T2 without him knowing, he always mentioned to me that his KTM 125SX had more pulling power. After I tested T2 and pump fuel back to back you can feel that T2 definitely brings more bottom end punch to the KTM’s engine character. Unlike the YZ125 where T2 doesn't need to be re-jetted, the KTM 125SX needs the jetting specs above to run efficiently and clean. This simple pour in mod runs you around $75.00 for 5 gallons, but to me this is a good alternative if you want some extra power on race day. 

If you have any questions please feel free to email me at kris@keeferinctesting.com 

Top 5 Money Mods And Top 3 Free Mods (Honda CRF450R)

Is there anything more beautiful than a brand new Honda CRF450R? Every time I walk out into the shop and I see that red machine sitting there, it just makes me want to go ride. However looks can be deceiving, because the Honda CRF450R can be a handful to ride on a fast, rough track that requires comfort. You see, the Honda chassis is on the stiffer side compared to other brands and with that stiffness comes a motorcycle that turns great, feels light when riding, but also gives the rider a harsh feel when hitting bumps. I’ll be completely honest here and tell you if the Honda didn’t have that stiff natured chassis feel in stock form, I would probably ride a CRF450R a hell of a lot more on my own time.

So in order to be able to call myself a “test rider” I better get off my ass and test some things that improve this machine right? These are five modifications that I have discovered while testing alongside Chad at XPR Motorsports. If you don’t know Chad, go back and listen to show #168 of the Keefer Tested Podcast. I have come to the conclusion that when I’m dealing with a 450cc motocross machine, I tend to flock to a bike with a smooth roll on power that is linear and long. Below are my “Top 5 Mods” that cost money as well as my “Top 3 Mods” that cost nothing. These modifications are geared towards calming the Honda down while getting more comfort out of the chassis. Once I did these modifications, it gave the Honda a feel that allowed me to ride the machine harder in rougher conditions.. It also made me want to load up this red machine first to go ride and leave the others in my shop. If you have any questions about these modifications please feel free to email me at kris@keeferinctesting.com. 

Vortex ECU Mapped By XPR Motorsports: The stock 2020 CRF450R mapping is an improvement over previous years, but it’s still simply too much on anything less than a freshly tilled up loamy track. In order to get more connection to the rear wheel and control you will have to get a Vortex ECU. This is not cheap, but rest assured this ECU, along with some of Chad’s maps have helped this chassis calm down. I usually am a “Map One/Two” kind of guy on the stock ECU, because it gives me more of a broad feel when trying to roll my corners correctly. I have tried a couple re-flashes of the stock ECU, but none have been as good as the Vortex system. The Vortex system gives you more parameters to work with and broadens the strong engine character, so that you are able to get on the throttle sooner, have more rear wheel connection, and most importantly doesn’t bind the already stiff natured chassis feel. In fact, this Vortex ECU helps the Honda feel less rigid because there is simply less engine braking with the maps we created. I have worked many hours with Chad in creating some linear maps that work for all levels of riding.

Akrapovic Evolution Muffler System: The Akrapovic muffler system shifts the Honda’s power around like no other muffler system I have tried to date. Once out on the track is when I realized that this Akrapovic muffler system could actually help this Honda chassis calm down. The Evolution system lets the Honda’s engine roll on smoother at low RPM’s and that smoother feel helps the rear wheel connection as well as provides less pitching (off throttle) than the stock system. AKA MORE COMFORT!!! The Honda CRF450R now builds a smoother roll delivery and a pulling power that is longer through the mid range than the stock system. This type of character can allow you to use second gear in corners more because the second gear hit is not as abrupt or quick and that doesn’t upset your technique or the chassis. The Akrapovic also allows the rider to shift later out of the corner with its increased over-rev capabilities. Pulling power up top is increased slightly as your shifting points can be altered now because of the longer pull in each gear. The mid range recovery of the Akrapovic is not as good as the stock system, but honestly that is not a bad thing. The Honda has so much power to work with that a little less “hit” as well as “recovery” actually helps me with cornering and allows me to be more aggressive on the Honda. I want to be able to ride this red bike and not let it ride me after 15 minutes into a moto. The Akrapovic system relaxes the engine as well off throttle. There is less  engine braking with the Evolution system and that also helps your fork from feeling harsh on small de-cel bumps. 

Custom Clutch Arm: The stock Honda’s clutch engagement point is very narrow and although the Rekluse Torque Drive Clutch pack helps the life/pull, the engagement is still too on/off for me. Chad at XPR Motorsports makes a custom clutch arm that really helps get an increased linear feel out of your clutch engagement. Not only is my engagement point wider, but it also delivers the power to the ground smoother, which in turn gave me more throttle to rear wheel feel. What does this mean? More consistent starts and better mid-exit corner rear wheel connection.”

Rekluse Torque Drive Clutch Pack: Rekluse offers a clutch pack (fibers, steels, springs) that replaces your OEM clutch plates and adds additional discs to your existing OEM clutch basket. It’s as easy as swapping your clutch plates into your OEM components. The TorqDrive thin friction disk technology allows more disks to fit in your OEM clutch’s footprint, decreasing slip and unlocking the full power of that Honda CRF450R engine. Once I installed the Rekluse system the clutch life of the CRF450R went up as well as rear wheel control on hard pack surfaces. The combination of the XPR clutch arm as well as this Rekluse clutch pack allows the Honda hook up better and gives me added control where the Honda needed it most, accelerating out of rough/choppy corners.

Pro Taper EVO Handlebars: I didn’t get to stick a pair of Pro Taper’s on until after my initial testing, but once I did I wondered why I didn’t do it sooner. The anti vibration quality of the Pro Taper Evo is superb as well as the comfort of the bar on jump landings/braking bumps. You might be surprised on how many riders actually use Pro Taper bars that are disguised as other bars on some big name motocross teams.

Top Three Chassis Mods/Tips That Cost You Nothing: 

Swingarm Pivot Bolt Torque Spec: Re-torquing the swingarm pivot bolt to 60 ft. lbs. helps with rear wheel traction as well as helps the rear end soak up small chop. This is only a small change, but can actually make a huge improvement. 

Engine Tilt: I stumbled across this mod when Chad at XPR unexpectedly did this without me even knowing. When I came off the track and commented I felt less vibration though my feet/handlebars as well as a better initial lean coming into corners he was kind of blown away. Since then I have tried this on another test bike and got similar results so I thought it was worth mentioning to you. The first step to tilting your CRF 450 engine in the chassis is to loosen off all motor mounts and engine hangers,(without completely removing the bolts or nuts) seeing how you are going to have to quickly tighten the motor mounting nuts while holding the engine in place. This includes the swingarm pivot bolt, lower engine bolt, three upper engine bolts that mount to frame and engine, finally the left and right engine hangers on the sides of the frame and engine. Next step is to find a long flat blade screw driver or a longer tire iron works best. Place the tire iron or screw driver in between the frame and the engine in the middle of the lower engine bolt and the upper engine bolts. By pushing down on the tire iron or screw driver you will notice the motor lift up and back in the chassis. While continuing to push down on the tire iron or screw driver begin to tighten the three upper engine bolts/nuts first and then the lower engine bolt /nut. Get these nuts and bolts tight enough to hold the engine in place without the motor sliding down again. Torque these four nuts to the manufacturers specifications then move to the swing arm axle nut and finally to the engine hanger bolts and torque them to the manufacturers specifications.

Top Engine Mount Torque Specs: Similar to the swingarm pivot, the top engine hangers play a huge roll in how the bike feels. I have tried aftermarket engine hangers on the updated 2019-2020 chassis and never felt confident that they did a good enough job to warrant the cost. To me re-torquing the top engine hanger bolts did a better job at creating a more compliant/calm frame feel when hitting square edge or braking bumps on straight line without sacrificing cornering feel. Doing this isn't going to make your Honda feel like a Kawasaki through rough sections of the track, but it will feel less firm when the track gets ugly. There are three bolts per engine hanger and you will re-torque the top two bolts that go to the frame at 20 ft. lbs. as well as the bottom bolt that goes into the engine to 37 ft. lbs. It’s not much but it does make a difference. 

Top 6 Mods To The Yamaha YZ125

My 14 year old son Aden has been going back and forth between two different colored 125’s, but has seemed to take a liking to the YZ125 the most lately. I decided see which simple mods could help this Yamaha YZ125 two stroke the most in order to get him some extra ponies. These modifications aren't supposed to drain your wallet, but instead will give you the most bang for your buck. Aden needed to graduate from an 85 up to a bigger machine, but needed a bike that could handle well yet be fast enough to pull him around. We stayed clear of the 250F’s for now and settled on a machine that was easy to ride for his 5’6 115 pound frame. The YZ125 to me was the safest choice as it isn’t as fast as a KTM 125 SX and handles a little better on rougher tracks. However, he’s at a level now where his balls are dropping and the throttle is getting twisted harder, so getting him a little extra horsepower was beneficial when we went to deeper tilled up tracks. Here are six very simple mods that we have done to the YZ125 in order to get more horsepower, but also keep reliability as well as some money in my bank account. These mods are set in no particular order, but getting a pipe/silencer combo with any of these mods should be first on your list of “must haves”.

FMF Factory Fatty Pipe/Shorty Silencer or Pro Circuit Works Pipe/304 Silencer: The FMF pipe/silencer combo adds a little more pulling power out of corners over stock, while the mid range on the FMF pulls slightly longer than stock and climbs farther through the top end. The FMF set up doesn't provide more over-rev over stock, but you will notice a healthier second and third gear pull down the straights. The YZ125 runs much cleaner with the FMF pipe/silencer (compared to stock) and looks stealthy as the silencer is hidden behind the number plate. I like that the FMF pipe comes with o-rings already installed and is ready to put on. The faster the track, the more this combination shined. MSRP: $397.00 www.fmfracing.com 

The Pro Circuit Works Pipe and R-304 silencer has a deeper sound than the FMF/stock system and gives the YZ125 more bottom end than the FMF. The PC pipe/silencer has increased pulling power out of corners (mid-range) and just feels like it’s more torquey. When rolling the throttle on you’re able just to feel more meat as you’re able to shift the YZ125 a little sooner. The top end signs off a little earlier than the FMF, but the Pro Circuit allows the rider to have more freedom with his/her riding without having to cover the clutch as much. MSRP: $396.00 www.procricuit.com 

VP T2 Pre-Mixed Race Fuel: VP Racing Fuels T2 blend is the company’s latest concoction of two-stroke motorcycle race fuel. Unlike their popular C12 two-stroke fuel, T2 is oxygenated in order to create more power. Recommended for either stock or modified two strokes, the VP Racing Fuels T2 comes premixed at a 40:1 ratio and is ready to pour right out the can. T2 contains no ethanol, which can help the engine parts in your YZ125 last longer. The 101 octane rating helps prevent against detonation, especially in high compression engines and works well with the Apex head. VP T2 gave the YZ125 better throttle response and a stronger bottom to mid range pulling power. At around 75 bucks for 5 gallons it’s an easy way to leave the ratio rite at home and get some more power for your next race. We didn’t have to change the jetting once poured in and the color of the spark plug was always nice and brown. MSRP: Check your local VP dealer www.vpracingfuels.com 

Jetting: Here are the 38mm Mikuni TMX jetting specs for sea level to 4000ft:

Main Jet: 430

Pilot: 40

Needle: 6BFY43-3

Clip: 2nd from top

Air screw: 2-1/4 turns out

V-Force3 Reed Valve System: The Moto Tassinari reed valve system is one of the best mods you can do to wake up the Yamaha’s engine. If you do nothing else but a pipe/silencer and a V-Force you will be almost on a level playing field with the KTM 125SX. The V-Force3 system gives the Yamaha increased power, throttle response and also allows the Yamaha to rev farther than that of the stock reed cage system. The V-Force reeds also last longer than the stock reeds and resist chipping much better. MSRP: $158.00 https://store.mototassinari.com/ 

Gearing: Going to a 13/49 from a 13/48 proved to be a better choice for not only my four stroke riding style, but my son’s nervous novice throttle hand as well. Going to a 13/49 gearing allowed me to have a little more grunt from second gear, but also let me shift sooner into third. Third gear still felt long and usable, but just gave the YZ125 a little more throttle response/recovery through the mid range. 

Apex Technical Innovations Cylinder Head: The objective of the Apex cylinder head is to improve upon the OEM combustion chamber shape to get more efficient combustion, while also offering interchangeability, as well as additional cooling from the billet design. A very important parameter of cylinder head design is the squish clearance. Because of manufacturing tolerances, the stock YZ125 head has a pretty large squish clearance for a 125 at around .050”. The point of the squish band is to shield and cool end gasses from the flame front to prevent detonation and to add turbulence to aid mixing and make for more efficient combustion. By having the squish clearance too big, like on the stock head, all the gas in that space is never forced to the combustion chamber and isn’t burned until too late of a crank angle to do effective work. This can cost you power, fuel efficiency, and make jetting more finicky. Also the flame front can creep into this space and actually cause detonation. 

The Apex YZ125 head is designed to have a nominal squish clearance of .035” which gives a great mix of reliability, safety, and performance. Apex then tuned the compression ratios, squish areas, and msv’s of each head profile to match the type of riding they’re intended for. The msv is the speed which the fuel air mix moves across the squish area into the combustion chamber and is another very important tuning parameter. Too high and the engine will be too peaky and risk detonation and too low and the engine will need excessive advance to run right and will be slow in general. The msv, compression ratio, squish area and squish clearance all affect each other, so a lot goes into getting the right combination.

Another unique problem that the stock YZ125 has is the way it has a flat top piston with a large bevel on the side. This makes conventional head designs not pair well with it. Normally one would have to choose an angle to match either the bevel part, or the flat part which leads to a compromise in how the squished gasses are dealt with. Using modern CAD and CNC machines Apex is now able to design the squish band of the head to suit the stock OEM piston shape. This way all of the fuel gets properly burned and you avoid detonation near the cylinder wall. 

Apex SX/XC insert has the highest compression, slightly higher than stock and has the highest msv that we’d advise running. This gives broad snappy power and a boost in power throughout the entire front side of the power curve. The mx insert has slightly lower compression than stock but an msv that’s higher than stock (but lower than the SX/XC) to let the bike rev out as freely as possible and give maximum over-rev. 

I installed the SX/XC Apex head in order to get Aden more bottom end coming out of corners so he could carry a taller gear. My son is only 115 pounds so having him carry third gear through corners wasn't a problem with the Apex head design. When I hopped on the YZ125, I couldn’t get over how responsive and clean the Yamaha ran with the Apex head. Apex said that we wouldn't get more top/end over-rev with this head design, but to me this head improved the power throughout the entire RPM range. Aden is more of a lugger (four stroke rider) than a revver and this allowed him to carry second and third more. Running a good race fuel like T2 or C-12 is recommended for this modification. MSRP: $200.00 https://www.apex-technical-innovations.com 

Top 7 Mods For The 2020 KTM 450SX-F

The KTM 450SX-F is one my top three 450’s to ride for 2020 and with a few mods it quickly becomes my favorite to ride. I usually try to keep these articles to just 5 mods, but I couldn’t leave out a couple key pieces that I really need on the KTM to feel comfortable on the track. These are in no particular order and if you have any questions about any of the mods you see below, please feel free to email me at kris@keeferinctesting.com.

Vortex ECU: I would like a little more excitement out of the KTM 450 SX-F’s bottom end so I asked Jamie from Twisted Development. If you’re fine with the KTM’s power disregard this tip, but if you want a cleaner throttle delivery, with more connection to the rear wheel, as well as more overall power, the Vortex is a huge advantage. If I was going to do one engine mod to this bike, this ECU would be it. The Vortex mapped by Twisted gives the KTM more bottom end, but gives me a more connected rear wheel feel when there is square edge. I am not spinning the rear wheel as much while getting more power. You will also get more mid-top end along with a longer pull in each gear. This ECU also allows the rider to work less by using third gear more through corners with increased recovery. To me the only negative would be the $800.00 price tag. Go visit td-racing.com or call 951 698 7222.

Rear Axle/Axle Blocks: Going to a Works Connection Elite axle block kit or Ride Engineering axle block kit will get rid of the fixed left axle block on the stock KTM’s axle. This will help the rear end to move more freely under throttle and improve the shock’s comfort on acceleration chop. Both are great, but you will have to decide if you want a complete axle/axle block kit like Ride Engineering’s  or just the blocks themselves like WC’s. www.worksconnection.com

Triple Clamps: After riding back to back with the stock triple clamps and the KTM hard parts clamps I have realized that the stock clamps are stiffer. I have since installed the KTM Hard Parts triple clamp (or the 2019.5 Factory Edition clamp) on the 2020 KTM 450 SX-F with excellent results. The front end has more of a softer initial touch on slap downs and the fork action is smoother on de-cel bumps. It’s crazy to think that the fork feels softer now with the “Hard Parts” clamp installed, but that is exactly how it feels when going to the “Hard Parts” clamp. I was able to increase my compression damping a little to help hold up off-throttle and kept more comfort through the entire stroke (with the stock AER fork) with the “Hard Parts” clamp. I also get slightly more lean angle front end traction (or cornering stability) with this “Hard Parts” clamp because the front end isn't bouncing around inside long/choppy ruts. www.ktm.com

Rear Brake Pedal Spring: Purchase a Honda CRF450R rear brake pedal spring with the rubber around the spring. The KTM rear brake pedal spring vibrates and will break every 3-4 engine hours. Orrrrrrrrr. Get a KTM rear brake pedal spring and wrap it with plastic tubing, but to me it’s easier just to get the Honda spring and be done with it.

Handlebars: The stock Neken handlebar is too stiff and doesn't offer too much comfort. Get yourself a set of Pro Taper bars and make your arms and hands happy again. The Pro Taper SX Race bar worked well for riders from 5’8 to 6’1. The SX Race bend comes in a crossbar or crossbar-less style and is 800mm width, 87mm height, 54.5 rise, and 54mm sweep. If you’re looking for a better “stand up feel” from your KTM look for handlebar close to this measurement. If you do like the stock bar try the Pro Taper Husqvarna Stock bend.  www.protaper.com

Muffler: To me FMF makes the best muffler system for the KTM 450 SX-F. There are some other companies that have other bikes dialed in more, but on the KTM, FMF has got it dialed. You will get more low to mid RPM response as well as more mid range pulling power. Top end is increased plus the over-rev is as good as stock. It is one of the few times that I was impressed because it was actually better than stock in almost all areas. The downside is that you must keep up on muffler packing (every 10-12 engine hours) because the FMF will blow out and that could damage your expensive titanium can. Did I mention that you will lose almost two pounds with this system? If you slap on spring forks you will be gaining almost three pounds. You can get most of that back with a 4.1 Titanium FMF Muffler system. www.fmfracing.com

Bonus Tip/Enzo WP/KYB Fork Conversion Kit (Husqvarna FC450): For $1595.00 you can upgrade your stock WP AER fork to a KYB spring fork. Enzo does this conversion and although it took me a while to try this (and on the FC450, I may add), I will say it’s one of the best fork mods I have ridden with on the FC450. This kit converts various current model WP front inner and outer tubes to accept the KYB AOS internal damping system. KYB AOS cartridge, rebound rod, compression base valve with standard caps, bottoming cones, springs and standard spring perches fit into the standard WP inner and outer tubes with the installation of the special machined conversion axle lugs. The damping and spring rate are set up for the individual customer’s requirements and the difference on the track is noticeable right away. Small bump comfort is a problem on the WP AER fork (on or off throttle), but the ENZO WP/KYB conversion gives you more front wheel traction/feel on small bumps and allows the rider to increase his/her lean angle more through corner via more front end traction. The KYB/WP conversion also doesn't have that mid stroke harshness like the AER fork can get late in the day and the damping control that the Enzo system has is much improved. Damping control is something that I want for performance when I start pushing the FC/KTM and the KYB conversion allows me to do this easier while being more in control. I will say the WP/KYB conversion still doesn't have the comfort like the Yamaha’s SSS fork on de-cel bumps, but compared to the AER fork, the WP/KYB conversion has more control when the track gets rough. I will be doing a comparison between the WP Cone Valve fork and the Enzo WP/KYB conversion on an upcoming RMATMC Keefer Tested Podcast.  www.enzoracing.com

2020 Yamaha YZ250F Top 5 Mods

Written By Michael Allen And Kris Keefer:

The YZ250F is one of the best 250 four strokes in class for 2020, but that doesn’t mean it can’t be made even better. Here are five easy and relatively inexpensive modifications that will make you love your 2020 YZ250F even more. 

1. Keefer “Free Feeling Map”: The mapping comes with Yamaha Power Tuner App is a great starting point to experiment with, but we have created a map of our own that we have fallen in love with. The “free feeling” map takes the superb torque feel and tailors it to make the bike feel free-er on de-cel. This “Keefer Free Feeling” map below gives you less pitching on de-cel coming into the corners and also made the Yamaha feel lighter through mid-corner, which helped cornering as well as change of direction. We felt like the YZ250F could give up a small amount of torque to achieve a stronger mid-top end, but with less chassis movement on or off throttle. Try this and tell us what you think? 

2. FMF 4.1 Titanium Muffler System: Although the stock exhaust is VERY hard to beat in terms of performance, it can get a little raspy once the hours start adding up. The FMF 4.1 system gives the bike a throaty tune and a factory look, but with a tunable engine character. We have found that running the system without the spark arrestor insert takes away too much back pressure, which causes the YZ250F to lose some of that bottom end power we come to love out of this bike. We prefer the system with the spark arrestor installed because it helps keep most of the stock bottom end, keeps the YZ250F quieter the bike, and can even make it legal to ride on the trails. 

3. Works Connection “Titan” Skid Plate: Mostly because we like off-road as well, but also because we believe all bikes should at least come with them. Let the consumer decide if he or she wants the skid plate on or off. We are sure it comes down to cost, but we can dream right? I mean Honda does it! Works Connection has been in the protection game for a long time with aluminum skid plates, but recently have now offered a composite piece. We prefer composite because it slides over obstacles easier than aluminum and doesn't affect the chassis negatively out on the track. In addition to having less friction, the composite has more flex that can allow the skid plate to slightly distort when hitting an obstacle and still be able to flex back to its original shape, as well as allow the frame to flex correctly under loads. The WC Titan skid plate is easy to mount, offers great protection coverage, and is one tough SOB.

4. Fire Power Battery: It’s no secret that a couple of our YZ250F’s had a slight issue with dead batteries and Fire Power has just the thing to alleviate this problem. We have had two stock Yamaha batteries that left us stranded so it was a no brainer to install an aftermarket Fire Power. Although it doesn’t necessarily make the bike start a lot easier, it never died on us, which is key. On top of that the Fire Power comes in at $120, which isn’t bad when you look at other competing batteries on the market. Although the difference is very little, the Fire power is also slightly lighter than your stock YZ250F battery. We are talking a couple ounces, so don’t freak out. 

5. Works Connection EZ Build Elite Perch:  Although technically speaking there is nothing wrong with the clutch pull on the 2020 YZ250F, there is nothing better than the feeling of a WC clutch perch and lever. The stock perch and lever have a quick adjust but while riding it’s not the easiest to adjust on the fly. With the WC assembly it’s much easier to roll the adjuster wheel with your palm without having to be super accurate. We feel like the clutch engagement is slightly better and less on/off feeling with the WC Elite system. On top of looking bad ass, the WC clutch perch is much easier to take apart and clean/lube than the stock clutch lever. Having a sealed bearing on the lever pivot makes for a much longer lasting, smooth pull, over the stock lever, which is just a greased bolt through a hole.  

Bonus Tip: If you want a little more hold up in your fork, but want to keep the comfort of the stock valving simply add 5cc of oil. By adding just 5cc’s of oil you will get a little more hold up, slightly less pitching under hard braking, and give you more front tire traction without pushing. Sometimes we feel the fork is too low when diving hard into corners causing our front end to wash out (especially on flat corners). 

Bonus Tip #2: You can also try chucking the Bridgestone X20 front tire for a Bridgestone M59 front tire. I stumbled across the M59 by chance, recently tried it and found it to be really good on lean angle/under load. The carcass of the M59 holds side loads better than the X20 or X30 and gives the YZ250F a more secure feel when under lean. I have not had enough time to rate the reliability, but so far the performance is better than the X20. If you’re one of the guys that complain about the YZ250F not cornering well then try this tire before you piss and moan.

If you have any questions about the top 5 mods you see here feel free to send an email to michael@keeferinctesting.com or kris@keeferinctesting.com. We are happy to help. 

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2020 Kawasaki KX450 Top 5 Modifications

Joe Oehlhof is in charge of the 2020 Kawasaki KX450 Keefer Inc. test machine. I like that Joe is hard on bikes and can really test the limits of certain parts of a machine. I asked him to send me his “Top 5” modifications that really improved the 2020 KX450. I didn’t want Joe just to write down his favorite shit about what he got for free, but put the parts he did get for “free”, into perspective for everyone reading this. Which parts that are on the Keefer Inc. Testing KX450 would he actually purchase himself if he went out and purchased his own Kawasaki. That is real to me. This is something that I would want to read. These are Joe’s “Top 5” modifications that he would get done himself, if he would be purchasing a new 2020 KX450 right now. -KK

1. Re-Mapped ECU By Pro Circuit: The stock power character is  strong, smooth pulling, and has good "snap" down low. However, while riding this bike in the 2020 450 MX Bracket Shootout and while building it for the World Vet National, I felt I needed to move the power around a bit, so I enlisted Pro Circuit to remap the standard ECU. I wanted 2nd gear to be broader and not ramp up as quick in order to give me a meatier, torquier feel as well as some added rear tire traction with less spin. I also felt like I wanted to use third gear sooner through/or after corners, so getting more recovery was needed. After I installed the re-mapped ECU, I could use third gear more and that allowed me to lug the bike better through corners, which improved my lap times. The added traction I got as well with the PC re-map was noticeable at Glen Helen when the track went to crap! -Trust me, Joe needs to use third gear more! He is like Barcia, but on a KX450! -KK

2. Pro Circuit Ti-6 Exhaust: Next, I went with Pro Circuit’s Ti-6 exhaust, which took the already very useable re-mapped powerband and gave it a boost. It added more torque down low without losing traction, made the throttle feel more "connected" to the rear tire, gave the KX450 a much improved, stronger mid range pull, and even more recovery that allowed me to grab a shift earlier out of corners. Lastly it improved over-rev/top end pull, which allowed me to shift less and if you know me, you know I like to hear that motor sing a little (don’t say a word Kris). -I already did, look above! -KK

3. Hinson Clutch Kit: A full Hinson set up was needed to handle the abuse that I give to the clutch so I went with the outer basket, inner basket, pressure plate, and a sweet looking cover. In stock form the clutch feel is a bit soft and spongy and the engagement point is a little vague. I like to know exactly where my clutch is engaging, which helps to not drag the clutch and gives it a much better/more positive feel on starts. Let me explain this…When you accelerate with the stock clutch system the bike starts to grab traction and then there is some slipping. It’s not the instant engagement or the feel of acceleration that I like and with Hinson’s set up, I was able to achieve the feel I was looking for.

4. Pro Circuit Re-valved Suspension: For a 190 pound guy the stock suspension is usually on the soft side, so of course Pro Circuit re-valved the fork and shock. I went a tad stiffer on the front fork spring, but for the shock, I eventually decided to stay with stock spring rate and used just a re-valve. I initially had a stiffer rear spring, but I lost a little of that initial plushness and comfort feel of the stock spring so we switched back to the standard spring rate and I was much happier. Rough square edge acceleration chop, big downhill kickers, OJ’s, and braking bumps are all handled much plusher with this shock re-valve setup.

PC was generous enough to let me try their A-kit internal cartridge set up, which fits directly inside the tubes of the Kawasaki KX450. These are awesome, but expensive! In stock form the forks ride a little low in the stroke for me, which makes the fork feel harsh on braking bumps. The action of the fork is comfortable, but the plushness of the fork gets lost around mid stroke. Pro Circuit’s A-Kit cartridge setup kept the front end up in the stroke when entering corners and gave me more front tire traction while braking hard as well as better bump absorption. I could be more aggressive yet still have comfort which is tough to do when it comes to suspension. -I can’t believe this “Average Joe” is running A-Kt forks. Wow! -KK

5. X-Trig ROCS Triple Clamps: These were the last modification I made and I'll admit I was surprised at the results. Now I know these clamps are pricey, but I honestly didn't know if they would improve the bike THAT much. I was also concerned that it would make my comfortable Kawasaki become too rigid. The stock clamps flex and twist a bit when pushed hard into corners, which gives the front end a slight vague/pushing feel. It wasn't until I went back to back with each clamp that I figured all of this out. If I would have never tried these X-Trig clamps, I would have never known the sensation of a stock clamp flex character. When I bolted the X-Trig ROCS clamps on I got a front end that was planted and predictable, but what surprised me was how plush the feedback to the bars were. I actually got improved front end traction on initial lean as well as through the middle of corners. Typically when a set of clamps has less flex you'll get a stiffer, rigid feel through the bars, but that is not the case with these X-Trig’s. -Joe running bling on his bike? This is crazy to me! Some bikes react better to aftermarket clamps and this seems to be the case with the KX450. -KK

2020 Kawasaki KX450 Vet National Race Build (Part One)

Written By: Joe Oehlhof

Five months ago, Keefer says to me while we were out riding, “Hey, you should race the Vet National.”  I responded back with, “Nah, it’s too much work getting ready for it.  I don’t have the time.” Of course immediately after Kris is done flapping his lips, his wife Heather chimes in with, “Yeah, you should race it. Kris will get you whatever bike you want.” My head sparked up and for some weird reason my mouth started to reply with, “Alright, in that case I am in”!  KK looks at Heather with a scoured look and says, “Wait, wait, wait…Whoa, Whoa, Whoa. You can’t be making those kinds of promises!”  A verbal agreement from any Keefer is a binding agreement so I immediately went Law And Order on his ass with “Nope, she said it.  That’s the deal.”  And Keefer replied with, “OK, we will get you a good bike and let you get it dialed in. Will you race it then?”  I reluctantly said, “Yes.”  Figuring it would probably never happen with Keefer’s schedule as well it being the fire season here in California (I am a San Bernardino County Fireman).  Never the less, we are roughly a week out from the Vet National and here I am preparing myself and a bike that I had about one month of time on.  

Getting the actual bike took a little longer than expected because of the “450 MX Bracket Shootout” and other factors, but in the end, Keefer decided to give me the 2020 Kawasaki KX450. Once he told me this, I got excited because I chose this bike as one of the top bike’s in this year’s 450 bracket. It’s a bike I feel really comfortable on, so I was excited to put some time on it, shake it down, and figure out what areas I wanted to address.

Luckily for me, Kawasaki provided a solid base to start from, which helps when you are in a time crunch.  The stock Kawasaki 450 is a great all-around bike for a wide range of riders, hence the reason why it got second in the bracket. For me the engine is strong yet very controlled, has a confidence inspiring compliant chassis, coupled with a smooth progressive powerband, that allows you to feel in control, while being able to push your limit. After spending a little over a week shaking this bike down, I came up with a few key areas that I wanted to improve. So here we go with phase one…

First area I wanted to concentrate on was the rider triangle which is really easy because I felt very comfortable with the stock bar position and bend. Call me old school but I do still like the 7/8” bar because of the flex that it provides. Kawasaki offers a lot of adjustability with several different bar position options with the triple clamp and two options with the foot pegs, but after trying several different combinations, I settled on the stock peg position and the bar mounts in the rear hole, facing in the forward position. Once I decided on this setup, I enlisted Pro Taper to provide that next level comfort. I went with the Carmichael bend Fuzion Bar because it’s a 1 ¼” bar, so you get the durability in case you have a crash, but comfort and flex of the 7/8” bar due to the option of locking or unlocking the cross bar. The locked position gives you a little firmer feel with less flex and the unlocked position gives you a bit more flex that mimics the character of a 7/8” bar.  Pro Taper also provided the oversized bar mounts, which easily bolted in using the rubber mounting and stock clamp. I rounded it out with the 1/3 waffle soft grips that added grip and comfort for my sissy hands.  

www.protaper.com

Next on the list of improvements was to boost the power for starts.  In stock form the Kawasaki KX450 provides a very broad manageable rider friendly powerband, but by no means is this bike slow. The power feels connected to the throttle, has excellent roll on bottom end with a strong pull through mid and top.  I had no complaints with the power delivery, I just wanted more. Don’t we all! I called the guys at Pro Circuit knowing that their relationship and years of experience with Kawasaki would provide me what I hopefully needed.  They sent me up with their Ti-6 Exhaust which provides a 1.5 pound weight savings as its titanium tubing is thing of beauty.  After bolting the system on (which is painless), I immediately noticed improvements throughout the power band.  It kept that smooth manageable roll on power, but increased it slightly, plus added more pull in the mid-range and thus improving the recovery time when shifting from second to third.  It also provided more over-rev just in case I got lazy (which is more common now that I am over 40) and I needed to leave the KX450 in second gear at times.  I know it sounds crazy to have a system that boosts power everywhere because usually it can be better in one area and not so good in another, but this system gave me exactly what I was looking for.  I have a couple more options to try to help move the power more, but that will be in phase two of this story so be watching for that.

www.procircuit.com

The last thing I was able to try in this phase of the Keefer forced “Vet National Bike Build” was another “comfort” piece. This piece made big improvements on the 2019 Suzuki RM-Z450 bike build, so we asked Kris Palm of FCP Engine Mounts to help me out for this green machine.  Factory Chassis Parts provided engine mounts with different a material and thickness (compared to stock) that allowed the chassis to flex differently yet shockingly provided a smoother overall feel, especially when the track is at its worst.  After a long day of testing with Keefer as well as doing two twenty-minute motos at Glen Helen, Kris from FCP bolted the engine mounts on and had me try them. If you have never ridden Glen Helen at 4pm just imagine a track that’s dry, most of the berms are blown out, has edgy off camber sweepers, kickers on the jumps, nasty braking bumps, and even nastier square edges through the corners, as well as down the next straight away. These conditions are commonplace here in California. If I was back home in Ohio, I may have not went this direction because of the soil differences, but since I am dealing with this kind of drier soil here on the west coast, I look for “comfort” when testing any part.  It’s miserable to ride a track as rough as GH when you’re not comfortable, but if you can make a bike work in those conditions, you have accomplished a great feat.  Like I said before, the Kawasaki chassis is (in my opinion) the best one out there, so I wasn’t sure if the FCP mounts would be able to improve upon that. In a nutshell, the mounts give the chassis just that little bit more flex, which takes away the transfer of energy that happens when you hit those bumps, so you don’t feel the sharpness of them as much. Upon entering corners, the FCP mounts take away some of that harsh hit you may feel and calms the movement of the bike down even more.  On initial lean through corners is where the mounts shine by allowing you to brake really hard and stick inside shallow inside west coast ruts.  Once in that rut, the bike stays planted and absorbs the acceleration chop better and continues down the next straight in a calmer manner.

www.fcpracing.com

I am really happy with the improvements we were able to make with bolt on parts and pieces from Pro Taper, Pro Circuit, and FCP.  Taking a good bike and making it a little better is always fun yet tough, so I am looking forward to phase two where I will be testing a remap of the stock ECU by Pro Circuit, modifying the suspension in order to dial it in for my weight and riding ability as well as a full clutch system from Hinson.  Stay tuned for that test as well as a Vet National story, to see how all of this preparation in one month’s time goes and the more difficult task of preparing myself with limited riding time due to firefighting duties, dad duties, and husband duties.  My hope is to give you guys that have regular jobs and family responsibilities a path to dialing in your bike, so you can enjoy that one day a week you get to ride. -Joe Oehlhof

If you have any questions about this test please feel free to email kris@keeferinctesting.com and he will try to do his best to answer any questions you might have.

2020 KTM 450 SX-F Start Up/Baseline Settings/Tips

The 2020 KTM 450 SX-F came to us with only minimal changes from the 2019 version, but since then we have gained some more knowledge because I have spent so much time on the 450 SX-F. Here are some baseline settings, suggestions, as well as some tips/modifications you can do to help increase the comfort of your new orange brigade machine. 

Engine/ECU: For 2020 KTM fixed most of the 450 SX-F’s ECU problems with the help of some of us media testers. Last year the 2019 ECU setting was rich off the bottom and slightly lean on top, which made for a lethargic/inconsistent throttle delivery. For 2020 the ECU is better and has a more lively feel coming out of corners and still has the super connected rear wheel feeling. I am usually a “map two” kind of rider due to its increased pick up/recovery feel, but sometimes I am looking for that extra puling power that is needed when the track is tilled deep or soft. I have been on the Vortex ignition bandwagon for a couple years with this machine and for 2020 it hasn't wavered. If you want the same great rear wheel connection as well as more pulling power everywhere, look into a Vortex ignition from Chad at XPR Motorsports or Jamie at Twisted Development. I have turned a lot of KTM riders onto this mod and have had a 100% approval ratio. What I like about this modification is that it doesn't hurt reliability and makes for a very usable yet powerful engine for almost every type of rider. Yes, it will set you back around $800.00, but to me is much better than slapping on a muffler system and will do more for your engine. 

Suspension: If you haven't listened to my WP XACT Pro Components suspension podcast you may want to at least check that out, but if you're sticking with the stock suspension for a while, you can try this setting to see if this helps comfort when the track gets rough. This setting below should be in the ballpark for riders around 165-200 pounds, but if you’re heavier than 200 pounds going to a stiffer rear spring wild help the ride attitude of the KTM. I have went to several tracks and tried many different settings, but this specific setting had the most “track toughness”. The KTM’s stock WP suspension doesn't quite have the comfort like the Husqvarna does, but the KTM/WP set also holds up more in the stroke. To get some added comfort back with the added hold up, try this setting. 

Fork (Stock Triple Clamp): 

Height: 5mm

Air Pressure: 10.7 Bars

Compression: 14-15 clicks out

Rebound: 16 clicks out

*With KTM Hard Parts Triple Clamps*

Height: 5mm

Air Pressure: 10.7-10.8 Bars

Compression: 12 clicks out

Rebound: 15 clicks out

Shock:

Sag: 103mm

Low Speed Compression: 13 clicks out

High Speed Compression: 1-1/2 to 1-3/4 turns out

Rebound:  12 clicks out

Chassis: Aftermarket engine mounts are all the rage right now and some of you may not have the money to spend on a pair of engine mounts for your KTM. I will say that I don’t feel like the KTM chassis is stiff, but I have heard from other vet riders that it can be at times, so I decided to play around with torque specs on the engine mounts and stumbled across this. If you’re experiencing a stiff feeling chassis sensation and want the KTM to settle while leaning (under throttle), there is an inexpensive way to achieve some extra front end traction (as well as an overall more planted feel). You can remove the left side upper engine mount bolt (upper right bolt only, as shown) and torque all other top engine mount bolts to 30Nm. This band aid will give you a more planted sensation when on throttle while leaning the KTM 450SX-F through sweepers and fast straights. You will have to make sure that all engine mount bolts have blue Loctite to ensure they do not back out (you should do this regardless if you keep all the bolts in or not). You can also try torquing your swingarm pivot bolt to 95 Nm (instead of 100Nm) to help rear end traction out of corners. The downside to doing these mods is that the chassis will flex a little more, so if you’re riding deep tilled tracks this modification may be too “flexy” for some (especially when chopping throttle).  

Handlebars: The stock Neken handlebar is too stiff and doesn't offer too much comfort. Get yourself a set of Pro Taper bars and make your arms and hands happy again. The Pro Taper SX Race bar worked well for riders from 5’8 to 6’1. The SX Race bend comes in a crossbar or crossbar-less style and is 800mm width, 87mm height, 54.5 rise, and 54mm sweep. If you’re looking for a better “stand up feel” from your KTM look for handlebar close to this measurement. If you do like the stock bar try the Pro Taper Husqvarna Stock bend.  

Triple Clamps: After riding back to back with the stock triple clamps and the KTM hard parts clamps I have realized that the stock clamps are stiffer. I have since installed the KTM Hard Parts triple clamp (or the 2019.5 Factory Edition clamp) on the 2020 KTM 450 SX-F with excellent results. The front end has more of a softer initial touch on slap downs and the fork action is smoother on de-cel bumps. It’s crazy to think that the fork feels softer now with the “Hard Parts” clamp installed, but that is exactly how it feels when going to the “Hard Parts” clamp. I was able to increase my compression damping a little to help hold up off-throttle and kept more comfort through the entire stroke (with the stock AER fork) with the “Hard Parts” clamp. I also get slightly more lean angle front end traction (or cornering stability) with this “Hard Parts” clamp because the front end isn't bouncing around inside long/choppy ruts. 

Rear Brake Pedal Spring: Purchase a Honda CRF450R rear brake pedal spring with the rubber around the spring. The KTM rear brake pedal spring vibrates and will break every 3-4 engine hours. Orrrrrrrrr. Get a KTM rear brake pedal spring and wrap it with plastic tubing, but to me it’s easier just to get the Honda spring and be done with it. 

Gearing: I like the stock 13/49 gearing, but for sand I prefer the 14/52 gearing for mid rpm recovery and chassis feel. Yes, going to a 14/52 will put your rear wheel back more than the 13/49 and get you some extra high speed stability with the 14/52. At tracks like Glen Helen I go with a 14/52 because I get that extra planted/stable feeling coming down hills. 

Rear Axle/Axle Blocks: Going to a Works Connection Elite axle block kit or Ride Engineering axle block kit will get rid of the fixed left axle block on the stock KTM’s axle. This will help the rear end to move more freely under throttle and improve the shock’s comfort on acceleration chop. Both are great, but you will have to decide if you want a complete axle/axle block kit like Ride Engineering’s or just the blocks themselves like WC’s.

Muffler: To me FMF makes the best muffler system for the KTM 450 SX-F. There are some other companies that have other bikes dialed in more, but on the KTM, FMF has got it dialed. You will get more low to mid RPM response as well as more mid range pulling power. Top end is increased plus the over-rev is as good as stock. It is one of the few times that I was impressed because it was actually better than stock in almost all areas. The downside is that you must keep up on muffler packing (every 10-12 engine hours) because the FMF will blow out and that could damage your expensive titanium can. Did I mention that you will lose almost two pounds with this system? If you slap on spring forks you will be gaining almost three pounds. You can get most of that back with a 4.1 Titanium FMF Muffler system.   

If you have any questions about your KTM please feel free to email me at kris@keeferinctesting.com. 

Top 5 Mods For The 2019 Yamaha YZ450F

Not everyone wants to “add” parts to their new dirt bikes, which is fine, but for those that must tinker, we put together a “Top 5” must haves that we would recommend. We will be doing these “Top 5” articles with all of the new 450F/250F machines and will be splitting the information up between pulpmx.com and keeferinctesting.com. These mods are recommended, by us, through countless hours of testing. If you don’t find a specific aftermarket company that you prefer in this article, don't fret, email me at kris@keeferinctesting.com and we can talk it out like adults should. Again, we will not push something on you unless we know it works. These mods that are in this article simply work for this specific machine. 

1. Fire Power Battery: The stock Yamaha YZ450F battery is a problem. It doesn't like to start in gear and if you do try to start it in gear for too long the battery will drain quickly. I have had countless emails sent to me about Yamaha batteries and the only thing I can tell you guys is go with an aftermarket lithium ion battery. I have been using Fire Power batteries in my Yamaha’s and they all have been great. Not to mention that they are lighter than stock, so losing some weight doesn't hurt. For around $125.00, it’s a fairly inexpensive way to prevent you from being stranded at the moto track with a dead battery. 

2. GUTS RACING Stiff Seat Foam And Gripper Seat Cover: Yes, we know Yamaha made some stiffer changes to the foam for 2019, but once the foam breaks down a little we are back in 2018 all over again and hitting the fuel tank when slamming into ruts. Going to a GUTS stiffer foam does wonders from smacking your butt bone into the fuel cell that lies underneath you. Does be scared off by the word “stiff” as the GUTS foam is stiffer, but not so bad where you will be getting monkey butt. I go with the standard stiff foam and not the phantom foam as I like the feel of the standard stiff foam more. While you’re at it go with a gripper seat cover and prevent your rear end from sliding under acceleration. The stock Yamaha seat is slippery after about 20 hours and will not hold you in place from that explosive Yamaha 450 power.  

3. Heavy Duty Chain: Like most stock chains the Yamaha chain will stretch and be smoked before the 8 hour mark, so get a good high quality heavy duty D.I.D. 520 ERT2 Gold chain. If you don’t mind the weight and the drag of an o-ring chain that is also a great choice. 

4. FMF 4.1 Full Muffler System: I am not going to sit here and tell you that you NEED an aftermarket muffler for the 2019 YZ450F, because you don’t. The stock muffler is so good on this bike that it’s not something you will need right away. However, I know most of you have A.D.D. when it comes to putting shit on your bike, so I will recommend a muffler that I had some help in testing recently. I helped George at FMF come up with a different setting inside the muffler (or core) of this system to create some more back pressure, in order to keep the bottom end that the stock system has. The FMF 4.1 system knocks off almost two full pounds of weight, retains the stock bottom end power, increases the mid range and top end, and will only lose minimal over-rev. I have tried a ton of aftermarket mufflers for the YZ450F and all of them lose bottom end. Not this one…  

5. Front Brake: The Yamaha front brake is not the best of the bunch when it comes to stopping power, but there is a modification you can do to make it insanely good (besides just throwing an oversize rotor on). If you want increased stopping power without the grabby feel, purchase an older Yamaha caliper (that used a bigger piston/part number shown) and an older KTM Brembo master cylinder (part number shown) while using your current 2019 YZ450F brake line and feel the magic coming into corners. You will be able to brake later and modulate the front brake better in shallow ruts than you can with the current front brake. This set up is also much more linear and less grabby than just throwing on an oversize front rotor as well. Just make sure to purchase the stock KTM banjo bolts and use your current 2019 YZ450F front brake carrier along with the current brake pad clip..