hey guys i have something i have been working on i cant seem to come up with a fix. on my 500i i have a problem right off idel. it will idel fine but if you rev up the motor and let off the gas it does not come back to idel very fast, it stay reved up for a few sec and then it will go back to an idel. any ideas. could this be a throtle cable issue are a vacume leak somewhere are a choke problem. i have checked these things out and can not find anything wrong. oh yea i have a k&n with a dj kit, using a 150 main and neddle clip third from top and air srew is 3 turns from seat, and have a hmf pipe as well.

 

Maximus; First of you have to realize these carbs have a vacuum operated slide and if the throttle valve is being used to set idle speed rather the the needle jet provide for that function the engine will be able to suck enough air past the partially open throttle valve, because the slide won't close that fast or far, to stay reved for a bit. The throttle cable is suppose to have slack(if I remember right the thumb lever is suppose to have a 1/4" of travel before you get throttle valve action) in it so the throttle valve will be closed and then you adjust idle speed with the **** on the stubby cable on the top of the carb.