One of my friends dropped his ct90 off at my house and said "fix it"...."Easy," I thought.... Well, I still cant quite nail it down... It will start with the choke on, but if I disengage the choke, it dies... In fact I can use the choke as a throttle as I open and close it... the choke fully closed makes the engine run almost wide open... I checked for air leaks around the manifold, but found nothing... Should I soak the carb in something unspeakable? please help... By the way, this bike sat for a long time.