91 YZ250 Jetting problems...

[harwood39]

Ok. I have worked on rejetting my carb. Im gettin frustrated with it. I have tuned it and it rips all the way through the throttle range. But, when its coming back to idle its slow at getting there and bounces a couple times... It seems to be running rich at idle, smokes at idle when warm but not anywhere else. New bottom end and top end, boyesen reeds, procircuit pipe and silencer. Im runnin a 40:1 mix with ams oil interceptor oil. In ND so not high elevation. air screw doesnt seem to do much.

Main Jet: 320

Pilot jet: not sure

Needle: Stock needle, 3rd notch

if anyone can help that would be great.

also there is some drool on the case coming from the cylinder/pipe fitting

[Synyster06Gates]

go down a size on the pilot?

[harwood39]

ya thats what i was thinkin, i havent touched the pilot jet yet...

[Synyster06Gates]

yeah; its most likely all you need

[harwood39]

once i play with the pilot circuit will i have to rejet the main?

[Synyster06Gates]

No all you need to do is take the old pilot jet out, screw the new one in. the main will stay the same.

[harwood39]

alright cool. should have done that when i had the bowl off... i love how easy it is to get to the main jet.

[Synyster06Gates]

haha oh yeah, makes things simple.

[harwood39]

ok. went down from a 40 to a 30 on the pilot, seems to have worked out the idle issue, but... it still doesnt wanna get back down to idle after a quick rev... its slow at getting there and im just stuck on it.... I might play with the mains some more...

Any other ideas??

[harwood39]

ok. well i have been doin more research. I have been told by a few people now to just tune the bike and take the idle out of it. Is it common for 2-stroke mx bikes to be tuned with no idle???

[Denn10]

thats a big just in the pilot i wouldnt keep it there you should go down a size at a time.

[harwood39]

i went down to a 35 first, runs good with a 35, but the best i could get it to idle was with a 30. It isnt running to lean now, its running great. no more spooge, no bogging. I might put the 35 back in since im setting it for no idle.