XT350 Idle problem

[twellens]

Hi everyone,

I have a '93 XT350 which starts and runs with the choke fully on, but once you turn it off the engine dies. I have given it some throttle, turned off the choke, and held the revs above 2000rpms, it ran fine. Higher rpms there is some back fire. This screams at me the mixture is too lean.

I've taken the carbs apart,ultrasonically cleaned them, and the bike is about the same, although it runs down to about 1200-1500 rpms now.

I've adjusted the air pilot screw, but it doesn't seem to have much of an effect.

Can anyone help me? Should I get new, slightly larger jets?

Thanks everyone in advance.