2022 Yamaha YZ250F GYTR High Performance Engine Kit

There aren’t very many OEM manufacturer accessory divisions out there that offer actual engine mods for their machines. Oh wait, there isn’t one! The only manufacturer that offers anything engine related is Yamaha. KTM used to have KTM Factory Services but that has been shut down yet GYTR is still going strong with a long heritage in the off-road world. I recently had the chance to test GYTR’s newest high performance YZ250F engine kit (which pulled me around to win the Keefer Vs. Keefer Part Two race) and thought why not dive into what is involved in the kit as well as how it differs from the stock 2022 YZ250F on the track. The 2021-2022 YZ250F GYTR kit comes with fully assembled cylinder head, high compression piston, air filter airflow kit, OEM gasket kit and a pre-programmed Vortex ECU for 3,199.00. GYTR also offers cams for this kit for an additional $699.99.

Durability Criteria: 

Being that I used to work for the GYTR YPAD division (Yamaha Parts Accessory Division) in the early 2000s I have had some experience with their criteria for the durability of these types of engine parts. When the engineers decide on a power that they are satisfied with on the dyno, the Yamaha R&D team will build up a machine and proceed to take it out to a few tracks to see if it is in fact better than the stock. Not only will it have to be better, but also make sense for the cost right? After the decision is made that the engine kit is deemed worthy for resale, the durability begins. Japan usually requires all accessory parts endure 1000km of life before it can be passed for quality control. I have been a part of other manufacturers durability testing procedures and have found out that none (so far) have been as detailed as Yamaha’s. So the good news is that when you purchase a GYTR engine performance kit, you’re getting something reliable and tested. 

On The Track:

I will say that when I first hopped on the GYTR YZ250F, I wasn’t blown away by the power. That is until I rode a stock YZ250F back to back. Once I rode the stock YZ250F is when I appreciated what the team over at GYTR did with this kit. I will not say the high performance engine kit has more low end RPM response as I think the stock YZ250F still has more initial response down low, but coming out of corners is when you’ll be able to appreciate the GYTR power. You can shift later in each gear and even allows this old guy to ride third gear in more corners than the stock YZ250F. This is huge especially for a rider that is coming off of a 450 which might have too much power, yet still wants to ride his 250F like a 450F. The stock YZ250F is one of the few 250F’s in class to allow some third gear cornering, but with the GYTR kit it can increase that window even more. Mid range pulling power is more meaty gives you the feeling of more torque in soft conditions. The GYTR engine feels freer revving than the stock engine and also has less engine braking which helps the chassis on rough tracks. Top end pull is not a huge difference over stock but you can feel the GYTR kit pull harder on top with a little more over-rev per gear than the stock engine. 

Things I Would Like To Improve: 

Even though I tested the GYTR High Performance Engine Kit with stock cams I think this engine could benefit from a longer top end/over-rev feel, which the GYTR cams can provide (tested them on last year’s engine). This engine likes to be short shifted, which is great for lugging or lazy riders, but for faster B class kids that love to rev each gear out extremely far, I still think the KTM and Honda have better top end over-rev capabilities. The GYTR engine package will reward you if you short shift which took me a while to pick up on, but once I did, this YZ250F was a weapon! I also would like to try the GYTR/FMF muffler system with the insert in, instead of with it out (like I tested). The insert in can give some added back pressure, which can give me some added low end rpm response. The FMF system could use some more bottom end and that could be the reason why the GYTR YZ250F lacks some of that low end RPM response. 

Is It Worth The Money?:

That is the reason why we do these articles and videos right? Of course this question is only good for people that are actually interested in doing some engine work. Do you NEED this kit if you just want to race local and have fun? Absolutely not! However, if you want to get a little more serious against your 450cc’d vet buddies or maybe want to get a little more competitive in the amateur racing world, to me this kit is worth the money. Going to some private engine builders to build your motor can cost anywhere between 2500-5000. Along with that, your bike will be down for at least a couple weeks, so getting a complete high performance engine kit that is tested in house at Yamaha is worth the money in my opinion. I do wish the GYTR engine kit gave some more top end/over-rev, but I am pretty sure you can get more of that with some cams and another map on the Vortex ECU. 

2020 Yamaha YZ250F Baseline/Start Up Settings/Tips

The Yamaha YZ250F is un-changed for 2020 so this baseline set up article can be used for the 2019 YZ250F as well. The Yamaha is the easiest small bore four stroke motocross machine to ride with its torquey low end and improved top end pulling power that Yamaha came up with in 2019. For this test we focused on trying to keep the comfort that the Yamaha comes with, but also try to get the YZ250F to accept a rider that wants to push his limits on this bike. Below are some settings that we think may be able to help drop your lap times while keeping the Yamaha planted underneath you. 

Suspension:  

The KYB/SSS/Yamaha suspension has the most comfort out of any bike in stock form, but if you want to start pushing the bike’s limits it can get soft and spongy feeling. After our initial test we took the 2020 Yamaha YZ250F to three vastly different types of tracks and noticed as the bike broke in all riders wanted more hold up from the suspension. We tried going to a heavier 4.8N/m fork spring (4.7N/m is stock) with the stock valving and to all three testers (160, 170, 190 pounds) liked the hold up and calmness that the stiffer spring came with. The heavier front spring helped the Yamaha’s chassis under heavy braking and each rider was able to push into rough corners harder without as much pitching. Settling into ruts was also easier because of the calm front fork feel. The rear of the bike can accept heavier riders better than the front so going to a stiffer rear spring for us wasn't warranted. What we really liked about this setting is that it didn't upset chassis balance and only improved the bike’s overall feel out on the track. Only a small increase of firmness was felt on the top of the fork’s stroke, but all riders agreed that the trade off was worth it. 

Fork: 

 Height: 5mm (Stock is 7mm)

Spring Rate: 4.8N/m (Stock is 4.7N/m)

Compression: 12 (Stock is 11 clicks out)

Rebound: 9-10 clicks out (Stock is 9 clicks out) 

*Optional Stock Spring Fork Setting*

Height: 4mm

Spring Rate: 4.7N/m

Compression: 8 clicks out

Rebound: 7 clicks out

Shock:

Sag: 105mm

Spring Rate: 55N/m

High Speed Compression: 1.25 Turn Out (1 Turn Out Is Stock)

Low Speed Compression: 8-9 clicks out (10 clicks out is stock)

Rebound: 9 clicks out (11 clicks out is stock)

ECU/Yamaha Power Tuner:

I really felt that the 2020 Yamaha YZ250F could benefit from a free-er engine feel on de-cel so I worked on a map to try and achieve this. This “Keefer Free Feeling” map gives you less pitching on de-cel coming into the corners and also made the Yamaha feel lighter through mid-corner, which helped keeping the lean through corners as well as change of direction. I felt like I could give up a small amount of torque to achieve this and that is what you will find when going to this map. You will get slightly less torque, keep that great mid-range pull as well as a slight increase in top end. If you want to also sacrifice a little torque feeling and increase the second and third gear pulling power (with the same amount of engine braking the stock map gives) go to the “Hard Hitting Map” Yamaha has pre-programmed on your Yamaha Power Tuner App. I use the “Hard Hitting” for my base map and the Free Feeling” map for my secondary map. Please don’t forget to update your apps on your phone as Yamaha does update their Power Tuner with new maps from time to time. 

Chassis: 

Please for the love of all things holy DO NOT screw/change the engine mounts on this machine. I will say that some aftermarket engine mounts will help some other OEM’s frame feel for the better, but in the case of the Yamaha YZ250F, it really doesn't need aftermarket mounts. I have no problem pushing products that work, based on each individual machine, but that doesn't mean that specific part works for every single machine. Some machines could benefit with a softer/stiffer mount combo, but to me Yamaha did a great job of blending comfort with cornering stiffness for 95% of us “normal” folk. When trying some aftermarket engine mounts on the 2019 YZ250F it made the bike have less predictability when the track got rough. When smooth I could see some benefit on initial lean through corners (lighter feel), but when the track got hammered the Yamaha was tougher to get into the corner because the damping character of the chassis was harsher on de-cel bumps. Could you make aftermarket engine mounts work on this bike? I am sure you could with the help of some suspension tuning, but the purpose of this article is to get you increased comfort/more performance with less hassle and money. If we were talking 2018 Honda or 2019-2020 Suzuki, I would be steering you into the aftermarket engine mount direction, but we are talking bLU cRU here people! 

Gearing:   

Two out of three test riders preferred the stock 13/50 gearing, but our slower heavier guy with less cornering technique liked going more the MXA (one tooth up) (13/51) route. Say what you want about going only “one tooth” up on a sprocket, but I can tell you that it does help on some machines with riders that have problems with using third gear in corners. The Yamaha has enough torque for intermediate type riders to use third gear in corners, but novices will appreciate a 13/51 ratio more to help them recover from mistakes. Going to this gearing will shorten the length of second and third gears, but it will allow you to short shift better and use the meat of the Yamaha’s power just like it was developed/intended. 

Seat: 

Do yourself a favor and get a 2020 YZ450F seat or a GUTS Racing firm seat foam. Yamaha changed the seat shape/stiffness in 2019, but still the middle of the seat can breakdown quickly and get soft. The fuel tank and subframes rails are not friendly when leaning on the edge of your seat or when you decide to seat bounce an obstacle out of a corner. 

Rider Triangle:

Yamaha’s rider triangle can be cramped for some taller riders, but simply going to the forward bar mount hole (on the triple clamp) with mount faced back will get you 16mm’s of more room. The 2020 YZ450F comes like this stock, but you can do that slight tweak yourself and get more weight over the front end. I am 6’0 and prefer the rear hole with the mount forward, but I have heard more than one taller rider complain about being cramped on the Yamaha. I have yet to try moving the pegs down/back, but will look into this as an option for you taller riders.

Maintenance: 

We have ridden the 2019 YZ250F a ton and although haven't had anything major go wrong with our YZ250F we did go through two stock batteries. Our YZ450F has never had a battery issue, but our YZ250F needed help in this area. We installed a FirePower battery in our test bike and had no other battery related issues. I also have received emails about timing chains going out and if we ran into this problem. The answer is no, but if you are a high revving, faster intermediate/pro type of rider, changing a timing chain every 20 hours is not uncommon. Follow your owners manual for regular scheduled maintenance, but just know that those maintenance schedules that Yamaha “suggests” aren't based on every type of rider. Each rider is different, but for the average rider/racer the Yamaha still has superb durability and is one of the few bikes that gives me less headaches during the course of the year. Please don’t believe everything you read on message boards and consider asking and trusting people and/or media outlets that spend a lot of time on these machines. I mean if I search up “headaches” on WebMD, I usually will read that I have some sort of Cancer and I should go to the hospital ASAP. Just because “Bobby Two Stroke” says Yamaha’s are ticking time bombs doesn’t mean they really are. Oh and you most likely DO NOT have Cancer, so everyone chill down. Sometimes message boards are a lot like WebMD, so proceed with some sort of caution. I am all not saying that a YZ250F’s will never blow up because they can just like any other machine. Take care of this bike and most likely it will take care of you.

Throttle Play:

Check your YZ250F’s throttle play when you get it home. Most of the units I have seen have had a ton of free play in the throttle. The bad news is you are not able to adjust it all the way out with the top throttle cable adjusters. You will have to adjust the cables play on the throttle body in order to get most of it out. After adjusting the throttle play on the throttle body, proceed to adjust the top throttle cable adjusters to get the desired free play. Throttle play is a preference, but to me there is way too much throttle play, off the showroom floor, on the YZ250F. I have went to a couple dealerships and blipped throttles just to check and most had A LOT of play. Check your throttle free play!   

Wear Items:

I am not a huge fan of the stock grips on the YZ250F as they feel fat, the chain guide and slider are actually pretty damn good on the YZ250F compared to other Japanese machines, sprockets and chains are your average 10 hour change out items, I go through clutch plates every 10-12 hours and I am fairly abusive on clutches, the 2020 air filter seals better thanks in part to a rubber grommet in the middle of the filter, but leave the backfire screen in for added dirt/particle safety, and the Bridgestone X20’s provide a good amount of traction and lean angle grip, but when they wear down slightly they are very un-predictable under hard lean angle.

If you have any questions about the 2020 Yamaha YZ250F please feel free to ask away at kris@keeferinctesting.com. Hopefully we can give you an intelligent and enlightening answer, but if we don’t know the answer to your question, we simply will reply with an “I don’t know”. We don’t know everything.

2020 Yamaha YZ250F On-Track Facts And Figures

Yamaha didn't change the YZ250F very much for 2020, but we did manage to get some added on-track information on Yamaha’s latest YZ250F and get you some feedback just in case you missed it in 2019. Below are some notes that should be taken into consideration about the changes Yamaha’s did make in 2019 and how the new 2020 YZ250F rides on the track. We will also lightly compare how the 2020 compares to the older 2018 model just in case you’re coming off of an older Yamaha YZ250F for comparison sakes.  

Also, just in case you missed the bold italics above, we say “very much” because some other media outlets are saying that NOTHING has changed with the 2020 YZ250F, but there is one small change and that may have been over looked. The filter element now has a rubber grommet to keep the element in place under the harmonics of the motorcycle while running. The 2019 filter element didn't seal that well, but with the updated grommet the 2020 seals much better. It’s not much, but it’s an important piece to a problem that the 2019 Yamaha had. 

2020 Filter Element

2019 Changes:

Yamaha kept the reward slanting engine design (for 2019 the engine is slanted forward 1 degree from the 2018) that already worked so well on the last model and made some changes to make it even better. Starting by adding electric start, Yamaha is the second Japanese manufacturer to have an e-start 250F motocross bike. The exhaust port shape was slightly modified so it transitions to the head pipe (which shape has also been changed to accommodate this) better and has increased the flow rate. Also in the head, Yamaha has increased the intake valve lift, and slightly changed the angle of the exhaust cam. The final changes to the new head are larger lifter buckets and slightly stiffer valve springs. Underneath the head, the piston crown has been increased, which has bumped the compression from 13.5:1 to 13.8:1.

 The throttle body on the 2019 changed from Keihin to Mikuni. It is 44mm and has a 12 hole injector. Also different on the throttle body is the cold start (choke) which now has to be pushed in to be activated and is deactivated by fully closing the throttle. Along with the engine changes and new fuel system, the ECU settings have been updated. The new dual electrode spark plug’s cap now has a finger holder keeping the cap firmly in place. The transmission side of the engine has also received key changes including a heavier duty clutch. What makes the clutch stronger is larger plate diameter, 6 clutch springs (one more than last year), and thicker steel plates (which in turn reduced the number of friction plates from 9 to 8). The transmission gears have also been updated and are using a high impact steel.

The new e-start is a compact, sits behind the cylinder, and drives the clutch basket directly. The 1.5 pound lithium battery sits under the rear of the seat and has a capacity of 2.4AH and 13.2volts. The amount of power the YZ 250F needs to generate has been reduced because of the addition of the battery which means there is less resistance on the stator/engine.

The frame on the 2019 has been majorly changed to make the bike feel more nimble on the track. The frame rails that go around the gas tank/air box are now straight where last year had more of an S shape. Other parts of the frame have been changed from forged pieces to extrusion aluminum, and the engine mounts have been changed from steel to aluminum. The material at the swingarm mount have been increased front to back and narrowed side to side, making the side of the frame flatter at the swing arm mount. The steering head has also been moved forward 6mm to help with stability.

In the past there have been comments about the seat height and width of the YZ 250F. Yamaha has changed that by making the seat slightly flatter, shorter, and narrower than last year’s model. Along with the seat, Yamaha has narrowed up the plastic where the rider’s knees contact the shrouds. The new shrouds have the air ducts integrated into them (same as 450) and the whole top part of the shroud no longer has to be removed to service the air filter. The air filter cover now only needs one Dzus fastener to be removed for access to the air filter which is no longer held in by a screw, instead it’s held in via rotating clips.

Yamaha tried to lighten the bike in 2019 up by using thinner, higher strength material for the handlebars, and also using lighter rims. To help with stability, they increased the surface area of the wheel collars where they contact the fork lugs and added more material to the rear collars. The KYB forks use new internals including a new piston, cylinder, mid speed valve, pressure piston, and stiffer spring rates (from 4.6N/mm to 4.7N/mm). The shock reservoir volume has been increased by 30cc and the coil spring now has less winds, is made of a thinner material (lighter), and the rate has changed from 54N/mm to 56N/mm.

On The Track With The 2020 YZ250F:

The 2020 YZ250F has great torque and pulling power down low, but doesn't quite have the top end pulling power like other bikes in its class. The YZ250F is so good at low rpm that it gives me the sensation that I want to ride a 250F full time. It’s that much fun! The Yamaha pulls hard out of corners and has a huge amount of bottom to mid range response that most will appreciate. There is enough meat coming out of corners that a wide range of riders as well as abilities can be left with the decision to leave it in second or third gear through corners. It’s a very vet rider friendly machine and gives the rider that excitement that we all look for in a bike. What is the downside? It does have more engine braking than the KX or CRF and I would like more top end pulling power through second and third gear. We worked on a different map to increase top end and also decrease engine braking. More on that below. 

 The firm feel of the 2020 chassis makes the bike feel planted and have a positive front end feeling through corners. Where the 2018 kind of felt lethargic/slow to react to the rider, the 2020 feels slimmer and more nimble (from the swingarm pivot forward) yet has a better straight line character on fast choppy tracks. The easiest way to describe the way the 2020 feels is that it has a fun cornering character with a confidence inspiring straight line feel. The 2020 YZ250F isn’t the leader of getting in and out of corners the quickest, but the planted feel in which it comes with is calming to any rider. The chassis still has a pitching (off throttle) sensation, but with a small change to the ECU, this pitching feel can diminish. The beauty is that if you want engine braking with a heavier front end feel, the Yamaha can give you that or if you want a lighter front end feel with a less heavier front end feel, simply going to the “Keefer Free Feeling Map” can give you that as well. Again, to me, this is a very well rounded chassis for a wide range of riders and abilities.  

 The 2020 KYB SSS fork is still the best fork out on the market. With the chassis changes Yamaha made in 2019, the KYB fork compliments those changes wonderfully. The fork does not dive as much on de-cel and stays up in the stroke more (especially with the KK map installed) than the 2018. The KYB fork does move in the stroke, but going 1-2 clicks slower on the rebound helped calm the front end down on g-outs or jump faces. Our lightest test rider liked he stock rebound setting on the fork, but if you’re slightly heavier going slower will be the better way to go. The shock likes to be set to around 104-105mm and it complimented all three riders that we used in this test. We set the baseline sag of 105mm to our middle weighted rider (170 pounds) and the other two riders (150 pounds and 195 pounds) thought the bike was balanced enough for them to push around the track. Traction to the rear wheel is apparent on the Yamaha when giving it the berries out of corners and it’s really difficult for the rear tire to step out coming out from a rut. On de-cel the rear of the 2020 Yamaha doesn’t have a vague light feel, which sometimes could leave you with that rear end “sliding out feel” and then that “oh shit” sensation like the 2018 version had. The rear end of the 2020 YZ250F feels heavier/planted (in a good way), which gave me the sensation of a more connected throttle to rear wheel feel (AKA, meaning a more planted/heavier feel).

 Stop with the Yamaha feels fat excuse. Every time I hear this I tell people “go measure your KTM and measure the Yamaha (at the shrouds) and get back to me”. Sitting on the 2020 YZ250F feels just fine because I feel more upright than “inside” the machine. The whole machine feels slimmer and flatter than the 2018, which to me will fit larger sized riders just fine. You will have to go with a stiffer foam after 10 hours or so, but that is an easy fix by calling Guts Racing. You can also go with the bar mount in the forward hole turned back if you need a little more cockpit room. I have tried this position and have come to like this rider triangle feel. The 2020 Yamaha YZ450F will come standard with this position, so I better get used to it.    

I really felt that the 2020 Yamaha YZ250F could benefit from a free-er engine feel on de-cel so I worked on a map to try and achieve this. 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. I felt like I could give up a little amount of torque that the Yamaha has to achieve this and that is what you will find when going to this map. You will get slightly less torque, keep that great mid-range pull as well as slightly increase top end. If you want to also sacrifice a little torque feeling and increase the second and third gear pulling power (with the same amount of engine braking the stock map gives) go to the “Hard Hitting Map” Yamaha has pre-programmed on your Yamaha Power Tuner App. I use the “Hard Hitting” for my base map and the Free Feeling” map for my secondary map. 

Bridgestone X20’s come standard on the 2020 Yamaha YZ250F and although I didn't like them on the YZ450F when I tried them they work well on the YZ250F, especially on front tire lean angle. I like that you can initiate your lean early on the font tire of the X20 and it will give you a positive feeling underneath you. The rear tire isn't quite as good on lean angle, but still hooks up in a wide range of conditions. I will say that the X20 has a better carcass feel than that of the Dunlop MX33 tires. I will take a Bridgestone X20 front tire all day over a MX33.  

Stay tuned for a settings article over on keeferinctesting.com as well as pulpmx.com for the 2020 YZ250F as soon as we got more time on the bLU cRU machine.

Living With The 2019 Yamaha YZ250F

After being in love with the previous model YZ 250F, I couldn’t wait to get my hands on the 2019. Once the initial introduction testing was over I got to spend some real time on the bike and have been struck by cupids’ arrow (once again). Almost every aspect of the 2019 YZ 250F has been at least slightly improved from the previous generation. I’ve now had the bike for around four months and put 20+ hard hours on it riding everything from tight/jumpy moto tracks to deep wet sand tracks.

One area that has really been improved is the mid to top pulling power for 2019. The previous model had amazing bottom end torque, but lacked excitement when the bike was being revved out as this engine loved to be short shifted. It’s no secret that the 2019 has more over-rev and more exciting power throughout the RPM range. However, there is a downside; in my opinion there is only so much power that a manufacturer can reliably get out of a 250cc motorcycle without creating a time bomb right? Yamaha already had the strongest 250F engine character, so to me it feels like what Yamaha did was move the meat of the YZ 250F power closer to the midrange instead of the bottom. In order to try and get the YZ 250F to have more exciting mid-top end power it lost a bit of torque out of corners. Kris (Keefer) has helped me a lot on mapping in order to make me happy and getting the Yamaha to have the best of both worlds. We came up with the Aggressive Keefer 2 (see photo for the number fields) map a couple weeks ago and it seems to work well everywhere. The new map got rid of the somewhat empty feeling (compared to last year) bottom end where if you were a gear high exiting a corner, the clutch would need a lot of massaging. Now I feel like I can exit a corner in a taller gear, using a minimal amount of clutch, to get the bike pulling down the next straight. The only place I feel this map is lacking is a bit of over-rev. There are times where I wish the engine would just pull a little longer in each gear, so I wouldn’t have to shift just before the next corner. (editors note: It sounds like Michael needs a 450 or get off his lazy ass. Bro! It’s a 250F, you must shift!) The next step is to try an exhaust system to see if it will give me more horsepower, but for now we are leaving the bike stock for shootouts. 

The chassis and suspension of the 2019 Yamaha YZ250F is another part of the bike that has been vastly improved. The previous model had a somewhat soft and slight wallowy feeling through g-outs and flat landings. The new chassis and suspension have a much firmer feel without being harsh. The front and rear of the bike ride slightly higher in the stroke and in g-outs/hard landings the 2019 doesn’t dive un-necessarily too far into the stroke. This firm feeling has slightly faded with the amount of time we have put on the bike (as the oil has broken down) and I have had to compensate by stiffening the compression clickers a few clicks (both front and rear). The other place this chassis really shines is through corners, whether they be flat or rutted, the 2019 has a much more of a planted feel. The previous generation tended to want to stand up in rutted corners and take a bit more input from the rider to lean in. This chassis takes minimal input to lean in, stays planted, and leans all the way through ruts easily. 

Test rider Michael Allen used to go in a straight line fast, but now he loves to rip up some moto.

A couple things that does bother me with the 2019 YZ 250F is the seat and exhaust. The seat, although made stiffer than the precious model, is still soft after it breaking it in. When seat bouncing or when seated while leaving a rut (with a square edge or hook in it) my ass blows through the foam and finds the top of the fuel tank. After long moto’s it leaves me with some soreness. GUTS Racing makes a cover and firmer foam that Kris will write about right here on the website. When the bike is new, the exhaust is on the loud side, but doesn't sound too bad, but after 10+ hours, it does get pretty blown out (raspy). The tone has gotten increasingly louder as well as quite annoying (especially for Kris when he’s riding behind me before I get lapped). The future plans for this bike are to compete in Keefer Inc’s 250cc shootout, then have some work done. What we’d like to do is focus on getting some more useable overall power from the Yamaha with an ignition and exhaust, then possibly get more extreme and install a higher compression piston as well as some different cams. The Yamaha has been reliable and I am still using the stock clutch! The Yamaha takes a licking and keeps on ticking! 

Keep an eye out for our 2019 250cc MX Shootout as well as the future build of this bike at Keeferinctesting.com. Also feel free to reach out to me if you have any questions about the 2019 Yamaha YZ 250F at michael@keeferinctesting.com. -Michael Allen

2019 Yamaha YZ250F Maps

Here are some maps for you to try on the 2019 Yamaha YZ250F. You can get these on the Yamaha website, but since I keep getting emails that say “I can’t find it”, now they’re right here for you to see! Enjoy! -KK

2019 Yamaha YZ250F First Impression

From Super to Superb 

Since Yamaha unveiled the all new YZ250F five years ago, it’s been a quality machine that has a lot of positives to it. Over the last five years, Yamaha has done a lot of fine tuning to chassis, engine and suspension, which made the YZ250F even better. In terms of making changes that make the YZ250F even better, 2019 is the biggest year for changes since its inception in 2014.

Before we get to how it works on the track here are all the changes for 2019, starting with the engine. Yamaha kept the reward slanting engine design (for 2019 the engine is slanted forward 1 degree from the 2018) that already has been in the loop since 2014 and made some changes to make it even better. Starting by adding electric start, Yamaha is the second Japanese manufacturer to have an e-start 250F motocross bike and as spoiled as I sound it’s a welcomed addition. The exhaust port shape was slightly modified so it transitions to the head pipe (which shape has also been changed to accommodate this) better and has increased the flow rate. Also in the head, Yamaha has increased the intake valve lift, and slightly changed the event angle of the exhaust cam.  The final changes to the new head are larger lifter buckets and slightly stiffer valve springs. Underneath the head, the piston crown has been increased which has bumped the compression from 13.5:1 to 13.8:1. 

The throttle body on the 2019 had changed from Keihin to Mikuni, is 44mm, and has a 12 hole injector. Also different on the throttle body is the cold start (choke) which now has to be pushed in to be activated and is deactivated by fully closing the throttle. Along with the engine changes, and new fuel system, the ECU settings have been updated and the new dual electrode spark plug’s cap now has a finger holder keeping the cap firmly in place. The transmission side of the engine has also received key changes including a heavier duty clutch. What makes the clutch stronger is a larger plate diameter, six clutch springs (one more than last year), and thicker steel plates (which in turn reduced the number of friction plates from 9 to 8). The transmission gears have also been updated and are using a high impact steel. 

The new e-start is a compact, sits behind the cylinder, and drives the clutch basket directly. The 1.5lb lithium battery sits under the rear of the seat and has a capacity of 2.4AH and 13.2volts. The amount of power the YZ 250F needs to generate has been reduced because of the addition of the battery which means there is less resistance on the stator/engine. 

The frame on the 2019 has been majorly changed to make the bike feel more nimble on the track. The frame rails that go around the gas tank/air box are now straight where last year had more of an S shape. Other parts of the frame have been changed from forged pieces to extrusion aluminum, and the engine mounts have been changed from steel to aluminum. The material at the swing arm mount has been increased front to back and narrowed side to side making the side of the frame flatter at the swing arm mount. The steering head has also been moved forward 6mm to help with stability.  

In the past there have been comments about the seat height and width of the YZ 250F. Yamaha had changed that by making the seat slightly flatter, shorter, and narrower than last year’s model. Along with the seat, Yamaha has narrowed up the plastics where the rider’s knees contact the shrouds. The new shrouds have the air ducts integrated into them and the whole top part of the shroud no longer has to be removed to service the air filter. In fact the air filter cover now only needs one Dzus fastener to be removed for access to the air filter which is no longer held in by a screw, instead it’s held in via rotating clips. 

Yamaha also tried to lighten the bike up by using thinner, higher strength material for the handlebars and also using lighter rims. To help with stability, they increased the surface area of the wheel collars where they contact the fork lugs, and added more material to the rear collars. The KYB forks use new internals including a new piston, cylinder, mid speed valve, pressure piston, and stiffer spring rates (from 4.6N/mm to 4.7N/mm). The shock reservoir volume has been increased by 30cc, and the coil spring now has less winds, is made of a thinner material (lighter) and the rate has changed from 54N/mm to 56N/mm.  

The Yamaha Power Tuner app, in my opinion, is one of the coolest features on this machine. You no longer need a stand-alone device to change the mapping of your fuel injected Yamaha; you can now do it from your smart phone via Yamaha’s app. All you need to do is take your side panel off (only the first time you use the app) and get the bikes serial number, then bump the starter button and connect to the Wi-Fi signal the bike puts out. Once connected you can pair the bike in the app and change mapping, record maintenance, monitor trouble codes and even log your races and track conditions. There is also a handlebar mounted map switch that allows the rider to switch maps on-the-fly. You can load a map from your Yamaha Power Tuner App, directly into your YZ250F and go back and forth between any two maps the rider desires.    

Now that all the changes and technical mumbo jumbo is out of the way let’s get to how all that correlates to on-track feeling. Starting with the engine, the 2019 YZ 250F has a more free-revving feeling than the previous model. Yamaha did a lot of work in the engine department on this bike  and tried to get added power from mid to top end and they definitely hit the mark.  When pulling down a long straight away, or trying to pull a gear a bit longer than the 2018, the 2019 will oblige and pull hard all the way to the rev limiter. This free revving feeling also results in a more playful power characteristic making the engine feel more lively because you aren’t having to short shift to stay in the meat of the power. All that being said, I feel like Yamaha traded a bit of bottom end pulling power in order to gain the top end power. The best way to describe it is the 2018 wasn’t as picky about what gear you needed to be in when exiting corners, you just maybe needed a flick of the clutch (recovery time) and the bottom end power opened up and started pulling. For 2019 you need to be a little more selective about what gear you are exiting the corner in, because if you are a gear high, it will take a bit more clutch work to get the engine into the meat of the pulling power. Although the 2019 slightly lacks bottom end power when compared to the 2018, in my opinion, it’s still ahead of the rest of the 250F field. The last thing in the engine department that needs to be mentioned is the new electric start. I like the fact that there isn't a clutch cancel switch so the starter can be activated at any time. That being said there was a slight hiccup from time to time. When the bike was in gear, it seemed to turn over just fine but struggled to fire at times. If the engine found the compression stroke with the clutch not all the way engaged the starter would stop spinning, and the button wouldn’t work when pushed for 2-3 seconds. After 2-3 seconds it would work as usual when the button was pressed; it almost seemed like an auto reset breaker would pop, then re-set itself and continue working. To combat this I would just try and make sure the bike was in neutral before starting it.  

Having the map selector on the bars is definitely a plus, and gives you two separate options that can be changed on the fly. The two maps that were loaded in the bike were stock, and “hard hitting”. Using the Yamaha Power Tuner app is very user friendly and I think one of the cool features is the maintenance recorder. It’s just reassuring to always know when the last time you did things to your bike was and it’ll tell you when it’s time to maintenance certain things again. Yamaha updates their maps that their test riders work on for you to be able to download and try. You can also as well make your own or try one that a buddy has made. We are all a bit scared of electronics, but I have to admit it’s kind of nice to be able to change how the bike runs with the push of a few buttons instead of re-jetting a carburetor. It’s also pretty damn cool that your bike will tell you what’s wrong with it in the app if there is a trouble code (I’ve tried waterboarding a carburetor and never got a straight answer out of it).

The chassis on the 2019 YZ250F is where Yamaha made the biggest improvements. The changes they made to combat some stability issues hit the mark and the bike is night and day better. Not that it was all over the place before, but I definitely feel that the bike tracks better in a straight line and has very little twitchiness to it. Usually when a bike gets more straight line stability it gives up a bit of cornering ability, this isn’t the case with the 2019. The previous model was hard to lean into corners and didn’t like staying leaned over, but the new bike has definitely instilled confidence in my inside rut abilities. Tipping into a corner takes less rider input and staying leaned while in the rut is much easier with the bike not feeling like it wants to stand up. I’m sure some of this comfort is also from the slimmer bodywork on the new model. The slimmer radiator shrouds are a very welcomed change and helped me keep my knees tighter to the bike and my leg tighter to the shroud when it’s up in ruts. This feeling is aided by the 18mm narrower seat at the tank, it’s also lower in the rear which I didn’t notice much, but may be more beneficial to shorter riders. 

Rounding out all the positive changes made to the 2019, the suspension has taken a huge step in the right direction. After spending a lot of time on the 2018 I felt that the suspension was too divvy (or had a pitching sensation). The new YZ 250F has a much firmer feeling to the suspension, not stiffer, just firmer. Let me explain myself; when going through rougher sections, the front and rear of the bike are still soaking up the bumps well, they just don’t seem to be transferring energy to the opposite end of the bike which caused the pitching sensation. There is no longer a wallowy feeling, like the suspension is using too much of the stroke, instead it does a better job of staying up in the stroke. On harder landings the bike no longer blows through the stroke, like I said before its firmer not stiffer, it retains a plush feel without giving the rider any harshness. 

With all these changes being made to the 2019 YZ 250F it’s going interfering come shootout time. Yamaha has really stepped up their game this year and showed themselves to be at the forefront of technology with the easy to use tuner app. The 2019 is offered in traditional Yamaha blue or white/cyan and has an MSRP of $8,299. Yamaha also offers their “bLU cRU” contingency program for motocross and off-road racers. In addition to the contingency, Yamaha also has free trackside assistance at certain races for any Yamaha racers.  If you have any more questions about the 2019 Yamaha YZ250F feel free to reach out to me at Michael@keeferinctesting.com or Kris at kris@keeferinctesting.com. -Michael Allen 

2018 Yamaha YZ250F Worn In, Not Worn Out

As my time with the 2018 Yamaha YZ250F comes to an end, I make no bones about it being my favorite 250F of all the 2018 models. Kris gave me this bike as my long term moto test bike, and in doing so has forced me to branch off from my off-road roots more than I have in the past. I’m sure it helps that I was somewhat familiar with the bike since I also love the Yamaha YZ250FX, but nevertheless Yamaha has made an outstanding machine. As previously stated I used this bike 95% of the time for moto, whether it be for racing, or just motoing down riding countless laps at Sunrise (Keefer’s favorite local track). Kris forced me to take inside lines, jump things I was scared of and ride 20 minute moto after 20 minute moto. In the 30+ hours I put on the Yamaha I never had to replace anything other than regular maintenance items. 

The 2018 YZ250F is like most current model motocross bikes, if you take care of them they will take care of you. I made sure to keep up on oil changes, air filter cleanings, chain tensioning and what do you know, I never had a bike failure. There are only a few items that wore out and needed changing to make sure the bike stayed in good running order, grips, a fork seal, a clutch, and a chain. The grips just plain wore through, the chain didn’t fail but just got clapped out, the clutch started to slightly slip when the engine was under a heavy load and the fork seal most likely got cut by roost. I am a working class guy that has to pay for his own parts (outside of Keefer Inc. Testing duties) so I can appreciate the durability of this machine. I was impressed that this bike could be ridden hard for months and the maintenance would have only cost $386.00. 

• Genuine Yamaha Clutch $181.19
• Genuine Yamaha Grips $19.02 (most people don’t buy these but Yamaha replaced them)
• Genuine Yamaha DID chain $71.39
• Oil and Filter Changes $75.00
• Genuine Yamaha Fork Seals $39.40 (both sides were replaced)

After around 20 hours the stock exhaust did get noticeably louder and a bit annoying which I’m sure is normal since I’d be willing to bet there wasn’t much packing left. The suspension started to feel a bit soft and lacked dampening as the stock oil broke down, which was changed when the seals were replaced. One thing I wish this bike came with was a skid plate or glide plate (no not some ridiculous off-road one). After a long day of doing motos, it’s a pain to wash all the baked mud off the bottom of the engine.  

I have to admit I’m a bit sad to see this bike go (maybe not as sad as Keefer was with the YZ450F) because it has helped me grow as a rider and has never let me down. I raced it at REM events, TWMX races placing 1st and 2nd and also did three days of seemingly endless tire testing. The 2019 models have recently been unveiled and from what it looks like the new bike received the same changes the YZ450F received in 2018, which should make the new 2019 YZ250F even better. I look forward to the 2019 (and Keefer) teaching me how to become more of a moto guy thus helping me progress as a rider and tester. But hell I guess until then it’s back to the trails I go while I still have the 2018 YZ450FX. -Michael Allen