I just got an 01 rm250 in really nice shape, but once I rev it to about 3/4 throttle, it starts sputtering and blowing black, like it's waaay rich. I figured it's most likely either jetted way to rich, or the exhuast valve is stuck/disconnected. In my manual, Suzuki calls for a 175 main, but all the mags said it came with a 162? It currently has a 178 main, fmf gnarly pipe, and powercore 2 silencer. I would appreciate any input.
thanks
thanks