new and little uneducated

[mihm82]

first off, im new to the 2 stroke world but not the bike world. i bought a 2001 cr 250 in august, had it rebuilt and now im kinda runnin into problems. im at the point of breaking in that i can git on it a little more, but i think my jetting is messed up. whenever the bands kick in, the bike smokes bad and kinda stumbles. it was jetted for a fmf pipe and silencer when the engine was probably worn a little. the jetting was fine before the rebuild, now would it be running to rich or too lean?




thanks



dan

 

[IndyMX]

Sounds like the main jet might be a bit rich

 

[mihm82]

thats about all that makes sense to me.

 

[spark250]

have you been lugging this thing around trying to "break it in"?

Sounds silly but it might be as simple as a spark plug. Sometimes when they are fouled the bike will still run but not right. especially in the higher rpm range. For $2 try putting in a new plug?

 

[spark250]

also, I used to have an 01 jetted to fmf specs for an sst pipe. The main was one size bigger and I think the needle position was moved 1. So, nothing radical there, it should still run fine unless the jetting is way out of whack!

 

[mihm82]

no, i did change the plug, and yeah after babyin it for 1 tank it was SHOT. i did clean my air filter good, and gonna put it back in wednesday and see what happens. also, i talked to a few guys at work and they ran into the same problem when they re-built their 125's

 

[IndyMX]

Time to buy some brass and learn how to jet.

Check motorcyclecarbs.com for cheap jets

 

[mihm82]

yeah, its a mikuni carb and i dealt wit those before so, i kinda have an understanding on how it works

 

[mihm82]

ok so the main that is in it now is a 400, im gonna git a 390, 380, 370, and a 360 just to be safe. im hopin its a 380, plus jetting this thing is super easy comapred to my rancher.