OK, here's my situation. 1980 RM250. Bike runs well, but feels blubbery on the bottom, yet when I sit and idle the bike and blip the throttle, it has a lean rev as the rpms come back down. I don't know how to describe that. The thing is, I foul plugs constantly. The bike is extremely easy to start with a fresh plug, but ride for a bit and it becomes more and more difficult and eventually won't run without a plug change.
I have checked compression, installed new boysen reeds, replaced the right crankshaft seal. New intake manifold, head and cylinder gaskets. I am sure I don't have an air leak or an oil leak, but my plugs foul constantly.
The jetting is close to stock but the needle and needle jet are no longer available and I used a slightly leaner counterpart that was available from Sudco. Float level has been set to factory spec.
Do I ignore the sound I am getting when blipping the throttle and go leaner on the pilot circuit? Mess with the main? (main feels OK by the seat of the pants measurement)
Where do I go from here?
I have checked compression, installed new boysen reeds, replaced the right crankshaft seal. New intake manifold, head and cylinder gaskets. I am sure I don't have an air leak or an oil leak, but my plugs foul constantly.
The jetting is close to stock but the needle and needle jet are no longer available and I used a slightly leaner counterpart that was available from Sudco. Float level has been set to factory spec.
Do I ignore the sound I am getting when blipping the throttle and go leaner on the pilot circuit? Mess with the main? (main feels OK by the seat of the pants measurement)
Where do I go from here?