My idle problem.
 

Lately I have noticed my 61 K&B when I go back to idle from full it takes 5 or10 seconds to go back to normal RPM.air leak or something? I cant figure t out.

My idle problem.
 

512 CES:

You got it on your first guess. You didn't say which carb you have (K&B supplied this engine with three basically different carbs, and variations of each) but they are all prone to air leaks at the mounting.

Best/easiest cure is to put a small bead of RTV around the base of the carb and reinstall it.

The rear crankcase cover also sometines will have the gasket fail, use the RTV trick here too.

If you have the Perry carb (black plastic body) you could have a leak from either the idle adjuster o-rings, or the o-ring inside the body of the needle valve. An o-rings kit is just a couple bucks from Conley or MECoA.

If you have the big cast block carb, (most had K/B engraved on the front but some early ones did not) and there is an air leak around the needle you'll have to replace the fitting the needle goes in. If the jam nut isn't tight enough vibration will wear the inside, no cure but replacement.

If you have the "Finned" carb with the K&B cast in the front face, it uses o-rings similar to the Perry - it's actually a K&B made version of the Perry, and the o-rings are similar. Get them from MECoA.

Hope this helps.

Bill.

My idle problem.
 

Thanks