Originally Posted by smokinbenrage
#1. I was playing with the air mixture screw when my bike was idling. I noticed that if I turn it clockwise the engine starts to rev higher. If I turn it counter-clockwise, it revs lower. My question is what is the best adjustment for the screw and if I have it too tight, will it reck my engine?
#2. My engine starts to make a bbbbbbbbbbbbbbb (not smooth) noise at certain throttle positions. When I twist it some more, it sounds like, mmmmmmmmmm (smooth). What could be going on with the engine? I asked my dad and he said that it is because the engine is out of balance... is this true. If so, how do I fix it?
1) Makes sense - because that is your idle screw.
2) Allow it to break in and then start adjusting stuff per all the threads here. (Not a matter or turning screws unfortunately)