New 450 EXC 2009 idle, rpm problem

[Mat_La_Falange]

Hi !

I just bought a new '09 450 EXC. I did 2.5 hours on it for now and i have some questions. I didn't do the mod for anti-polution, jet and pipe.

First the bike was always stalling at idle so i turn the screw and now its seem ok. Also have hard time to let it run at a cold start. I put the choke its juste fine ... after couple sec the rev start to go up, close de choke and than the bike stall. I have to run on the choke on it a bit and after that its ok.

The main thing is that when i close the throttle the bike still rev for a sec ou two. It seem to be worst when i pull the clutch and when i put it neutral the rpm drop right away. During those secondes, i have no compression at all and the bike want to accelerate if im cruising and just pull the clutch.

Is it a jetting issue ? Clutch issue ?

I also got some steam that came up one time when i was doing tight woods and try to pass somewhere. I shut it down, waited a couple minutes and after that it was ok.

I just want to be sure if its normal ... or i should go check it ?

[Cold Smoke]

I didn't do the mod for anti-polution, jet and pipe.

Totally normal.

https://www.thumpertalk.com/forum/showthread.php?t=797315

https://www.thumpertalk.com/forum/showthread.php?t=783122

https://www.thumpertalk.com/forum/showthread.php?t=353125

https://www.thumpertalk.com/forum/showthread.php?t=328819

[Mat_La_Falange]

ok so the mod will all fix that ?

[Cold Smoke]

ok so the mod will all fix that ?

That seems to be the consensus.

JD Jetting (Be sure you follow the recommendations for elevation and temperature)

Pull off the emissions stuff

Cut the pipe

Re-gear (13/48 or similar and you can keep the stock chain)

Replace coolant with something like Engine Ice, Coolanol or Cool-Aide

[Mat_La_Falange]

ok thanks !