hey guys what’s up, I did a rebuild on my mikuni42, cleaned the hell out of that thing and let me tell you it was a world of a difference, before if I would give it somewhat full throttle it would shut off, now it hesitates a little bit but goes up real fast, the only thing im noticing is I cant seem to control the idle to go under 900-1200 rpm..... any suggestions???

 

Could be that the AF screw isn't set correctly? There is a lot of advice out there about "this many turns" is best. But the best way to set that is to let the bike warm to operation temerature, and with the idle around 1000. Turn the screw in until the engine starts to miss, then back it out, counting the number of turns, until it once again starts to miss. Then go back to between those two points. That is where it should be. If it goes all the way in without missing then the pilot jet may need to be changed out. If it is more than 3 1/2 turns out that is another sign you may need to try differnt sized pilots.

make sure you have a tuning manual with it.