250R Problems......

[TonawandaRider]

I recently had the motor on my 84 250r bored 75 over..... i odv. upgraded the piston rings crank etc.. the only thing I didn't upgrade was the carb. bc it was in excellent condition. After putting the motor back in the bike i was having problems with it running right. i have rejeted the carb. 4 times playing around with different jets but cant seem to get it running perfect..... Any suggestions

[Dirtcrasher]

If all you did was freshen it up and get everything tight again (no exhaust or airbox mods), then your jetting should have been very close.

Not sure how you made your jetting changes?? Make one jet change at a time, write it down and read a fresh spark plug. Take the A/B lid off, is it worse? If it is you were already too lean.

Is an air leak possible??

You should not need major changes to jetting.........

[250rmanfmf]

How is it running? Will it not stay running? Does did sound like its not firing and some Ratations? Could be a number of different things