Upgrade to enjoy this feature!
Vital MX fantasy is free to play, but Premium users receive great benefits. Premium benefits include:
- View and download rider stats
- Pick trends
- Create a private league
- And more!
Only $10 for all 2026 SX, MX, and SMX series.
My 24 kx450 will roll a bit when shifting to first from neutral. I can it a bit of throttle with the clutch in and it seems to stop rolling. I tried googling and it seems this is normal? Thoughts? I replaced my clutch lever with an arc lever and changed the ratio to 19, but I think it was doing this before I replaced the lever today it was just super noticeable when I was testing it out.
Probably time for a flush and bleed.
Has anyone experimented with the airbox, beyond the Twin Air Powerflow kit? I knew about the plastic being gutted and already went through with gutting mine out, but I’ve heard about both the US and MXGP factory teams running a bigger air filter, even that PRMX is allegedly running a 2017 CRF 450 filter with a custom 3-D printed cage. Vital Pit Bits from High Point shows a rare photo of the inside of the factory airbox.
@ML512 do you have any info on how they accommodate a filter like this?
From my understanding it’s just custom factory air boxes. Febvre & pro circuit both have similar filter set ups as this photo.
The closet I see available to us is the twin air flow kit. Which is what I run on my bikes. I’ve been racing a lot of off road & I’m much more confident in the twin air flow kit set up for off road conditions & time of riding!
The Shop
Luxon 4-Post Bar Mounts
$189.95 - $239.95
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Free shipping: VITALMX
If anyone is struggling to get your KX450 forks dialed in, I’ll share what I did to get mine working better. I wanted more hold up, increased bottoming resistance, and still wanted to maintain the plush hand feel the stock forks have. I achieved this and best part is, this only cost me about $120 and a few hours of time. I have had a lot of revalved suspension sets over the years, and these forks, with these simple mods, feel as good or better than anything I have ever ridden. For reference, I’m 180 lbs vet intermediate rider and I ride prepped MX tracks.
I increased the spring rate from 5.0 n/m to 5.1 n/m, increased fork oil height in both forks from 320ml to 340ml, and slowed the rebound 3 clicks (12 to 9). This totally eliminated the bottoming I was experiencing with the stock forks and the diving under braking. All while still maintaining a great hand feel. I can now push through jumps and land in breaking bumps without the fear of bottoming or the bike getting unsettled. Good stuff.
Current fork setup on my 2025 KX450:
5.2 n/m spring in right side fork
340ml of fork oil in both forks
12 out on Compression
9 out on rebound.
I did a lot of troubleshooting with mine before getting them in a good spot. Currently back on stock springs with 370ml oil. 14 out on compression 9 out on rebound. Slowing the rebound the last few clicks to 9 from 12 seems to have me in a sweet spot. I’ve raced 3 weekends in a row with this setting now and it’s night and day over stock, mainly with oil height I think. I was bottoming with the stock 315, went to 350….still was bottoming on landings I shouldn’t have been…went to 370, and it’s great right now, might go 5 more, but 370 feels real good for now.
165lb vet intermediate, 40 years old.
Thanks for sharing your oil height experience. I’ll keep that in mind if I need to further stiffen my setup as the forks continue to break in.
I had the same feeling you did when slowing the rebound down to 9 clicks out. Settled the front end and got the feeling I was chasing.
No changes to rear shock setup?
Only clicker adjustments to the rear shock. I’m using the “Keefer Inc Testing” baseline setting, which is stiffer on all circuits vs the stock settings. 1.25 out on HSC, 10 out on LSC, 12 out on rebound, 104mm sag.
The link below should take you to Keefer’s website where this 2025 baseline setting is found.
https://www.keeferinctesting.com/2025-450-mx-baseline-suspension-settin…
I dropped one rate on shock spring and am running 1.25 HSC, 12-14 LSC, and 9-10 rebound. The shock has been pretty good. Any changes I’ve made to the shock have been easy to feel.
I can’t remember what spring rate front or rear RaceTech hooked me up with. I think I’m running clickers at stock. Older I get I can’t remember crap! The older I get the slower I get too!
I have the SR for starters. I’ve run the stock gearing and also added a tooth, but went back to stock. Adding a tooth makes 2nd gear shorter and slower so not as useful on faster parts of the track and big jumps and it doesn’t really help you with 3rd much. The stock gearing leaves 2nd more broad than any 2nd gear I’ve ridden and is fast enough to hit some big jumps without having to shift to 3rd so stock is my preference.
Me too. I run the stock gearing. I holeshot yesterday, too, so stock gearing gets the job done! I can carry third pretty easily in all but the tightest corners, and that just because I’m not as committed to the rut as I should be.
This is my fear of going up from the stock 50 to just a 51 and why I was curious if anyone tried to go up to a 52. I feel the 1 tooth change would have me in the same spot you found yourself in so I'm hesitant to even try a 51.
These manufacturers have so much R&D for these bikes. I truly believe that items like sprockets are the best available combo stock majority of the time. Obviously that can change depending on track and skill but majority I think it’s best.
My first 24 I put a full pc , ecu , 1 tooth up, airbox cut up and the optional engine mounts.
Loved it until I rode my unmolested 24. The complete stock bike felt phenomenal.(I do have kyb on it )
Eventually I cut the airbox and removed the baffles out of the stock exhaust, still love it.
I’m 240 and go fairly decent and can run 3rd in most corners. I will say in third it is a tad bit slow to rev up. Now I’m wondering if an exhaust would help.
Spent the weekend trying each xpr map and really didn’t notice much performance difference.
Mine is set to be delivered tomorrow from them through R+L Carriers....when you got yours, I am assuming they had a way to get the crate off the truck, correct? Lol
Correct, the R&L truck should have a powered lift gate and powered pallet jack. The driver will take care of the off loading.
Pit Row
Wanted to update my post with new settings…. My bike felt amazing on a softer track with a deeper sandy base and that’s why I made my original post. It worked amazing.
But yesterday, while riding a track with a harder base and some pot holes exiting the corners, it felt too stiff on the forks and shock. I ended up softening my setup front and rear and really got it working great. It’s nice to see the bike react in a positive way with just a few clicks.
New settings for a more hard packed track base:
Fork comp 14, reb 8, oil height 340ml.
Shock I went back to all stock clickers. HSC 2, LSC 11, Reb 13.
The forks did bottom once when I made a mistake, but I would certainly expect it to in that particular situation. No bottoming on normal laps when I’m hitting my marks.
How many hours has everyone got now? I’ve got 103hr. Still on stock clutch, valve train, and piston pulled it down to do a head gasket as I blowed it racing an off-road race but was really surprised how good the piston looked. Only issues I’ve really had was head gasket blowed, subframe cracked at 100hr. Otherwise just normal maintence. Twin air powerflow kit, and rotella t6 15-40.
I mean those are two pretty serious things brother.... why did the head gasket go?
Where did the subframe crack?
I’m at 95 on mine, did piston and clutch at 60 hours, about need clutch again been getting carried away with my left finger lol.
Only mechanical failure I’ve had is a blown counter shaft seal.
I am at 35 on my 2025 and my biggest fear is engine life with the Kawi after coming from a Husky. Your post makes me happy
Rotella gang!
Reading lots of posts, I hear these bikes are super amazing in performance and reliability.
I came from a ktm350. I bought a 19 kx450 and got over 300 hours with just clutches and a top end. Got a new 24 when those came out and have had good luck so far. On the 19 you could say some of the wear items wore out quick but I really think any idea of the engine being more susceptible of blowing is false. Shit happens with ever brand but as a whole.
It had cracked towards the back, close to the exhaust mount. The head gasket was my bad, doing an off-road race and it hadn’t rained here in over month stupid dusty and got involved in a pileup on a hillside and overheated the bike trying to get up it. Excuse the nasty soapy stuff on the exhaust I was in the middle of cleaning and going through the bike when I found the crack.
Interesting about the crack, I'll keep an eye on mine. My 25 has been great, a revalve by Enzo and the bike does everything I want it to. All my kx450s have been incredible bikes.
Yeah it’s definitely an odd place for it to crack. Especially since I haven’t seen anyone else having any issues so I’m gonna chalk it up to just being a fluke deal.
Were the subframe bolts loose? Those bolts do not like to stay tight so gotta check em. If they get loose enough it could cause a cracked subframe.
Post a reply to: 2024 Kawasaki KX450 and KX450X