I just bought a "new to me" 1981 XR200R. The only reason I even own it is to master riding wheelies on it, and for the most part it runs great. But after about 20 minutes of wheelie practice, it misses (doesn't fire) on some strokes. This only happens, though, when actually in a wheelie. With both tires on the ground, it never misses a beat.
I suspect mixture issues to be the cause, but I don't know if it's too rich or to lean. I have 90W-140 gear oil on the foam filter, which is pretty hard to wring out, so the airflow may be restricted. I examined the spark plug, a Champion RA8HC, and it looks normal to me. I have fiddled with the pilot screw, but did not notice any significant change. The main jet is a Keihin 138.
Thanks,
I suspect mixture issues to be the cause, but I don't know if it's too rich or to lean. I have 90W-140 gear oil on the foam filter, which is pretty hard to wring out, so the airflow may be restricted. I examined the spark plug, a Champion RA8HC, and it looks normal to me. I have fiddled with the pilot screw, but did not notice any significant change. The main jet is a Keihin 138.
Thanks,