Here are two sets of maps to try on your 2021-2022 Kawasaki KX450. The Chavez map will help the jerky throttle response from 0-10% throttle opening and give you increased mid range power. The smooth map will help rear wheel traction on slippery hard pack tracks.
Smooth Map:
Chavez Map:
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.
Kawasaki has a brand new KX450 without the “F” people! Who needs more “F” in this world anyway?! Seriously though, Kawasaki has a brand new 450 and it is probably the most anticipated motocross machine of 2019. I headed down to Pala, California last Tuesday night to attend the presentation that Kawasaki had for the media, to get a feel of the new parts that are on this 2019 KX450 machine. Kawasaki has a lot of R&D invested in this bike and definitely are looking for some great results come shootout time. The 2019 KX450 is available now at our local dealers and cost $9,299.00. Will it be in the hunt for a shootout win this year? It’s quite possible, but first things first, let me break you down some things I felt on the first day of testing so you can get an idea of what this bike is all about.
Engine Feel Compared To 2018 KX450: Ummmm…No comparison. The 2019 comes on quicker with a lighter, more free-revving feel! I am usually not a guy who likes to de-tune a stock 450cc motocross bike, but the Kawasaki simply is too crisp from 0-5% throttle opening. Yes, too crisp! Where you feel this 0-5% is when you are barely on the throttle through ruts. The KX450 gets jumpy with the stock green coupler and it upsets the chassis, which makes you very inconsistent through corners. Once the black coupler is installed it controls that 0-5% and gives you an incredible, yet smooth pulling power that feels similar to a KTM 450 SX-F. The mid range has a ton of meat and the increased top end/over-rev is noticeable on the second lap. I felt like I lost zero mid to top end pulling power with the black coupler (compared to the stock green one) and I could ride the KX450 more aggressively through corners. The engine is super connected to the rear wheel and never steps out coming out of corners. This is an impressive power plant! After I was done testing I was chatting with McGrath and he even said he preferred the black coupler. So there’s that, if you don't want take my word for it.
Cornering/Chassis: The new 2019 KX450 is more cornering “neutral” than in previous years. I am able to get more front end bite than last year, but also am still able to rear steer the green machine very well too. I had a rear end steering tester with me at the intro and he liked how well it backed into corners as well as I liked the front end bite from mid-end corner. I say mid-end because the KX450 still does have a slight vague feel on entrance of corners. Raising the fork up 2mm in the clamp helps this feeling somewhat and gives you increased front bite.
Suspension Comfort: Thank you Kawasaki and sweet baby Jesus for the return of spring forks!!! The 2019 Kawasaki is so much more balanced than last year’s bike and I was able to set the front end down where I wanted to without feeling like the front end was going to snap my wrists. The fork has tons of comfort, but is also too soft for my liking. At Pala there are some sizable jumps and the fork bottomed at too many times. Going stiffer on the compression only hurt de-cel bump comfort, so I settled on going slower on the rebound, which helped some. The shock is soft as well on slap down landings, but going eight clicks (two turns) in helped keep the rear end up and thus helps wallow feeling.
A-Kit Style Fork: When asked about the Showa A-Kit style fork to a Showa technician, I was told that this is truly an A-Kit style fork. When the Showa tech saw the drawings of the 2019 KX450 in its pre-production stage he thought it was a race team fork at first glance. Many parts that are inside of this production Kawasaki Showa spring fork is what comes inside the factory boys forks.
Weight Feeing (Chassis): I was told that the 2019 Kawasaki KX450’s frame is 1.87 pounds lighter than it was in 2018. The total weight of the new machine has only increased roughly three pounds from 2018, but to me it feels lighter than the 2018. Why? I feel it is because of the way the 2019 Kawasaki makes its power. It is very free feeling and snappy which makes this bike have a very light feeling through corners. I am ale to lay it down with ease and cut down under a blown out rut almost as easy as a KTM/Husqvarna. I do get a little twitch on de-cel, but it wasn't a horrible or un-easy feeling. Straight line stability is still the same straight and arrow Kawasaki feel that you expect. The frame absorption is one of the Kawasaki’s strong points and although the Pala track wasn't rough, there was some hidden square edge that I managed to hit during the day to test this.
Hydraulic Clutch: The Nissin hydraulic clutch feels nothing like a Brembo or Magura. The Nissin hydraulic feel is a little bit of cable and hydro. What the hell does that mean Keefer? It means that there is a little play in the Nissin hydraulic lever that makes it feel like a cable pull initially. Unlike a Brembo where there is no play and is very touchy (on/off feel), the Nissin has more of a progressive feeling. So far I prefer the Nissin feel over the Brembo. I like to ride the clutch a little with my finger while I ride, so having that little bit of play makes sure that I don't burn up my clutch as quick. The clutch feeling as you would expect was superb and I had zero fading or lever movement while riding. Kawasaki is the first Japanese manufacturer to have a hydraulic clutch on a motocross machine. Impressive!
Muffler: Ehhhhhh boy, here we go! Everyone complaining about the bazooka of a muffler from the 2019 Kawasaki. Yes, it’s long. Yes, it’s not that attractive, but the muffler tone is ten times better than the 2018. I will gladly take a long muffler that sounds good and provides excellent power delivery. This bazooka does just that!
Rider Traingle: The footpeg to seat to handlebar ratio is also another improvement. The seat is flatter, which puts me more on top of the machine than “in” it like last year. I like this feeling and it makes maneuvering on the bike better for my 6’0 frame.
7/8 Handlebars: Some manufacturers go away from 7/8 handlebars but Kawasaki keeps them around and I approve! They flex, they offer better vibration characteristics and unlike what most people think DO NOT bend THAT easily. I have crashed my brains out on 7/8 bars and they didn't bend as bad as I thought. I can live with 7/8 bars on a production machine.
Brakes: Kawasaki also went to work on the front and rear brakes of the 2019 KX450. The rear brake has a 250mm rotor (which is the largest rear production disc on a motocross machine), new master cylinder/hose and the front brake also has a new master cylinder. I would have to say that the front brake was more impressive than the rear because of how good its modulation was. It wasn’t a grabby feeling front brake and was more progressive to pull in. I could drag the front brake more through corners without getting that stabbing front end feel. I didn't notice that much of a power difference in the rear brake compared to the 2018, but it still worked well enough for me. Kawasaki riders that update to a 2019 will be able to feel the front brake improvements on their first ride.