2024 Kawasaki KX450 and KX450X

6/29/2026 6:20pm
NicNak wrote:
She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

IMG 0573 5.jpeg?VersionId=u4qU7MDP266MdTatGOd4kxqpye3pIMG 0574 5

Yowza

crmx105
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6/29/2026 7:04pm
NicNak wrote:
She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

IMG 0573 5.jpeg?VersionId=u4qU7MDP266MdTatGOd4kxqpye3pIMG 0574 5

Did the bike run on it's side for any amount of time? Someone posted on here a while back if they sit for a while bike should be turned over while holding the kill button to get oil pumping? 

NicNak
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6/29/2026 8:42pm
NicNak wrote:
She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

IMG 0573 5.jpeg?VersionId=u4qU7MDP266MdTatGOd4kxqpye3pIMG 0574 5

crmx105 wrote:
Did the bike run on it's side for any amount of time? Someone posted on here a while back if they sit for a while bike...

Did the bike run on it's side for any amount of time? Someone posted on here a while back if they sit for a while bike should be turned over while holding the kill button to get oil pumping? 

Run on its side? Like I crashed & it was running while laying down? No it didn’t. 

I mean that kind of makes sense but how long is a while? I ride quite a bit & I do go back & forth between bikes but I’ve been riding this one only for the last month or so. Raced it Saturday then Sunday on the site lap it didn’t make it 

crmx105
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6/30/2026 7:05am Edited Date/Time 6/30/2026 7:14am
NicNak wrote:
She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

She goneeee. 2025 kx450 with 55 hours. Did a top end at 45. 

IMG 0573 5.jpeg?VersionId=u4qU7MDP266MdTatGOd4kxqpye3pIMG 0574 5

crmx105 wrote:
Did the bike run on it's side for any amount of time? Someone posted on here a while back if they sit for a while bike...

Did the bike run on it's side for any amount of time? Someone posted on here a while back if they sit for a while bike should be turned over while holding the kill button to get oil pumping? 

NicNak wrote:
Run on its side? Like I crashed & it was running while laying down? No it didn’t. I mean that kind of makes sense but how long...

Run on its side? Like I crashed & it was running while laying down? No it didn’t. 

I mean that kind of makes sense but how long is a while? I ride quite a bit & I do go back & forth between bikes but I’ve been riding this one only for the last month or so. Raced it Saturday then Sunday on the site lap it didn’t make it 

Yes during a tip over. Regardless that stinks! I believe on the 19-23 model some were going back to the roller bearing rod setup. That may be an option? Also an engine builder told me to run a 50 weight multi grade in bikes with plain bearing cranks. Not saying that would have prevented it? Good luck with everything!

1

The Shop

NicNak
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6/30/2026 3:06pm
crmx105 wrote:
Did the bike run on it's side for any amount of time? Someone posted on here a while back if they sit for a while bike...

Did the bike run on it's side for any amount of time? Someone posted on here a while back if they sit for a while bike should be turned over while holding the kill button to get oil pumping? 

NicNak wrote:
Run on its side? Like I crashed & it was running while laying down? No it didn’t. I mean that kind of makes sense but how long...

Run on its side? Like I crashed & it was running while laying down? No it didn’t. 

I mean that kind of makes sense but how long is a while? I ride quite a bit & I do go back & forth between bikes but I’ve been riding this one only for the last month or so. Raced it Saturday then Sunday on the site lap it didn’t make it 

crmx105 wrote:
Yes during a tip over. Regardless that stinks! I believe on the 19-23 model some were going back to the roller bearing rod setup. That may...

Yes during a tip over. Regardless that stinks! I believe on the 19-23 model some were going back to the roller bearing rod setup. That may be an option? Also an engine builder told me to run a 50 weight multi grade in bikes with plain bearing cranks. Not saying that would have prevented it? Good luck with everything!

thanks man. Interesting you say that. Maxima makes a 20w-50 oil & i was using that for a while but it seems to turn into like a sludge material in the bottom of the clutch so recently went back to 10w-40. 

Yea it is unreal how these bearings suck. but my buddy told me it's the same bearing they run in vehicles & they go forever. He said if they starve for oil they are shot. I race pretty competitively & have had good luck with my kawi's since 2019 so we'll be alright. I put a crate motor in that bike & have my mechanic splitting & getting a parts list. The whole top end looks great actually. Head, cylinder, piston

1
Markee
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8/1/2026 1:30pm

Have you guys seen oil blow by the crank case vent? 

Noticed oil on the van floor, looked up and it came from the vent tube, had got on the lower shock pretty bad. 

55 hours. Ran fine that last moto. Oil change every 5 hours.

 

8/1/2026 1:34pm
Markee wrote:
Have you guys seen oil blow by the crank case vent? Noticed oil on the van floor, looked up and it came from the vent tube, had...

Have you guys seen oil blow by the crank case vent? 

Noticed oil on the van floor, looked up and it came from the vent tube, had got on the lower shock pretty bad. 

55 hours. Ran fine that last moto. Oil change every 5 hours.

 

You sure it isn’t shock fluid?

Markee
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8/1/2026 2:47pm
Markee wrote:
Have you guys seen oil blow by the crank case vent? Noticed oil on the van floor, looked up and it came from the vent tube, had...

Have you guys seen oil blow by the crank case vent? 

Noticed oil on the van floor, looked up and it came from the vent tube, had got on the lower shock pretty bad. 

55 hours. Ran fine that last moto. Oil change every 5 hours.

 

You sure it isn’t shock fluid?

Not shock fluid. Now I did get a kick off a bigger jump my last lap,  rode the rev limiter pretty long which I never do unless I need to. 

NicNak
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8/1/2026 3:14pm
Markee wrote:
Have you guys seen oil blow by the crank case vent? Noticed oil on the van floor, looked up and it came from the vent tube, had...

Have you guys seen oil blow by the crank case vent? 

Noticed oil on the van floor, looked up and it came from the vent tube, had got on the lower shock pretty bad. 

55 hours. Ran fine that last moto. Oil change every 5 hours.

 

You sure it isn’t shock fluid?

Markee wrote:
Not shock fluid. Now I did get a kick off a bigger jump my last lap,  rode the rev limiter pretty long which I never do...

Not shock fluid. Now I did get a kick off a bigger jump my last lap,  rode the rev limiter pretty long which I never do unless I need to. 

Yea that's the overflow. Too much oil in the bike. Probably did not quite get it all drained out then after doing that a few times it has a tad too much oil in it & blows it out the overflow. I'm not 100% certain that's what happened but that's a possibility.

mxrose3
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8/1/2026 3:33pm

You sure it isn’t shock fluid?

Markee wrote:
Not shock fluid. Now I did get a kick off a bigger jump my last lap,  rode the rev limiter pretty long which I never do...

Not shock fluid. Now I did get a kick off a bigger jump my last lap,  rode the rev limiter pretty long which I never do unless I need to. 

NicNak wrote:
Yea that's the overflow. Too much oil in the bike. Probably did not quite get it all drained out then after doing that a few times...

Yea that's the overflow. Too much oil in the bike. Probably did not quite get it all drained out then after doing that a few times it has a tad too much oil in it & blows it out the overflow. I'm not 100% certain that's what happened but that's a possibility.

That, or possible piston/ring blowby.    If the cylinder or rings are worn, the crankcases will be under constant pressure, forcing some oil out the vent tube.

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Markee
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8/1/2026 5:56pm
Markee wrote:
Not shock fluid. Now I did get a kick off a bigger jump my last lap,  rode the rev limiter pretty long which I never do...

Not shock fluid. Now I did get a kick off a bigger jump my last lap,  rode the rev limiter pretty long which I never do unless I need to. 

NicNak wrote:
Yea that's the overflow. Too much oil in the bike. Probably did not quite get it all drained out then after doing that a few times...

Yea that's the overflow. Too much oil in the bike. Probably did not quite get it all drained out then after doing that a few times it has a tad too much oil in it & blows it out the overflow. I'm not 100% certain that's what happened but that's a possibility.

mxrose3 wrote:
That, or possible piston/ring blowby.    If the cylinder or rings are worn, the crankcases will be under constant pressure, forcing some oil out the vent...

That, or possible piston/ring blowby.    If the cylinder or rings are worn, the crankcases will be under constant pressure, forcing some oil out the vent tube.

Did a compression test. Was 75 psi. Internet said 60 to 114psi based off a 12:5:1 compression ratio. I'll do a leak down tomorrow. 

Put my camera down there. Everything looked good, plug looked good. 

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Markee
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8/2/2026 7:13am

Found no smoking gun with the leak down test.

I'll put my eyes on the oil pump, make sure that's good. 

 What if the case vent got pinched, built pressure then released? I did find it in between pull arm and shock bottom.

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mxrose3
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1 day ago
Markee wrote:
Found no smoking gun with the leak down test.I'll put my eyes on the oil pump, make sure that's good.  What if the case vent got pinched...

Found no smoking gun with the leak down test.

I'll put my eyes on the oil pump, make sure that's good. 

 What if the case vent got pinched, built pressure then released? I did find it in between pull arm and shock bottom.

That could do it too.

1 day ago

25 KX 450SR with 60 Hours & 25 KX450 SR with 14 hours - Does anyone have issues with bolts coming loose on these bikes? Specifically the subframe bolts? I have to tighten them every time I come off the track. The same with the exhaust bolts. I ran a long moto on Thursday and one of the subframe bolts snapped and I'm going to have to drill it out. My steering stem nut likes to loosen up frequently as well. I have it torqued to right spec and if I over tighten the steering gets too tight. 

1
1 day ago
motoxxx599 wrote:
25 KX 450SR with 60 Hours & 25 KX450 SR with 14 hours - Does anyone have issues with bolts coming loose on these bikes? Specifically...

25 KX 450SR with 60 Hours & 25 KX450 SR with 14 hours - Does anyone have issues with bolts coming loose on these bikes? Specifically the subframe bolts? I have to tighten them every time I come off the track. The same with the exhaust bolts. I ran a long moto on Thursday and one of the subframe bolts snapped and I'm going to have to drill it out. My steering stem nut likes to loosen up frequently as well. I have it torqued to right spec and if I over tighten the steering gets too tight. 

I was having the issue with lower subframe bolts. Tapped and Replaced with bolt not oem stuff and it’s been fine. 

Shawnh
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1 day ago
motoxxx599 wrote:
25 KX 450SR with 60 Hours & 25 KX450 SR with 14 hours - Does anyone have issues with bolts coming loose on these bikes? Specifically...

25 KX 450SR with 60 Hours & 25 KX450 SR with 14 hours - Does anyone have issues with bolts coming loose on these bikes? Specifically the subframe bolts? I have to tighten them every time I come off the track. The same with the exhaust bolts. I ran a long moto on Thursday and one of the subframe bolts snapped and I'm going to have to drill it out. My steering stem nut likes to loosen up frequently as well. I have it torqued to right spec and if I over tighten the steering gets too tight. 

I have a 25 SR with 71 hours and I did lose the subframe bolt once around 20 hrs but it was right after servicing the shock so I think I just didn't torque it enough.  I haven't had any issues since then.  I've never had issues with the exhaust or steering stem.  I am pretty good at checking most of the bolts right after the first few rides but other than that, I ride it and generally have no issues. 

Vols
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1 day ago

Just picked up a new 2026 KX450. Other than the usual new bike prep, any tips or suggestions on what the new KX needs? 

crmx105
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1 day ago
Vols wrote:

Just picked up a new 2026 KX450. Other than the usual new bike prep, any tips or suggestions on what the new KX needs? 

If you are going to run the stock filter set up def get some Twin Air or some other after market air filters. The stock filter compresses paper thin on against the air box. If you want more power removing the screens from the stock muffler helps considerably. I used a flexible wood bit going in from where it fits to the header pipe to get the center one and a regular wood bit on the muffler tip side to rip the screens out. The wood bit grabs the screens without disassembling the muffler.

1
mshea397
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Fantasy
1 day ago
motoxxx599 wrote:
25 KX 450SR with 60 Hours & 25 KX450 SR with 14 hours - Does anyone have issues with bolts coming loose on these bikes? Specifically...

25 KX 450SR with 60 Hours & 25 KX450 SR with 14 hours - Does anyone have issues with bolts coming loose on these bikes? Specifically the subframe bolts? I have to tighten them every time I come off the track. The same with the exhaust bolts. I ran a long moto on Thursday and one of the subframe bolts snapped and I'm going to have to drill it out. My steering stem nut likes to loosen up frequently as well. I have it torqued to right spec and if I over tighten the steering gets too tight. 

I safety wire the exhaust so I don't have to over-torque fittings on the frame that I don't want to worry about.  

1
prozach
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1 hour ago
Vols wrote:

Just picked up a new 2026 KX450. Other than the usual new bike prep, any tips or suggestions on what the new KX needs? 

Blue locktite everything you can think of before you ever ride it . You will never lose a bolt.  If you don't.  You will lose many.  

Other that that.  Twist the throttle and go!  Great bikes stock.  

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