i think i know what it was. i was riding yesterday and it was doing it again. at the next stoplight i look down and the choke is on. i shut it off and it went away. the thing is, that choke lever is really easy to turn and i think sometimes, if i'm going fast enough, the wind could make it switch to the choke position. anything i can do about that? an expert helped me put the carbs back together. i am confident about them. also, when there is some hesitation only when my bike is going past 50 mph, does that mean one or both of my high speed jets has problems? when i slow down to under 50 mph, the problem goes away. would the fact that i have a passenger on the bike matter? my girlfriend and i go out for rides sometimes.