The motor doesn't want to stay at a consistent idle, will burble around 12-1300 for around 30secs and then starts to die, like a change in circuit or something not real drastic, but persistent. Floats are adjusted right, I think it is not running in the idle circuit and I am having to crack the throttle blades open, if it revved it takes a while to return. carb has primary throttle blades drilled and all new gaskets. I have previously used it on several motors but it sat for 5 years hence BG kit. If I had a vacuum leak wouldn't vac be really low and want to totally die? Had around 10hg and that is typical for my cam. The problem persists with or w/o vac advance. Timing is kind of whacky, have it set to 16 initial, since curve card says 20 @ 2700, but at 2900 total was 32. The motor wants a lot of timing. I Need some real answers if someone has some.

Does it only happen when fully warmed up?

-Mark.

Seems to be the case started briefly today it idled with the air cleaner on not warmed up yet, was doing it totally warm yesterday. What were you thinking?

No need to post in more than one place.

-dnult

I am thinking maybe fuel percolation. Too much heat causing the fuel in the carb to boil. It will cause those symptoms at warm idle but it will be fine when the engine is cold. I would need more info to give a better guess. Is it a fresh build? Just started happening with no other changes? etc.

-Mark.