I have a chevy small block 350ci with a four brl carb.the problems I am have are,with the engine running I place my hand over the carb air inlet and the engine speeds,when removed engine slows down,also on carb one of the idle mixture screws does nothing when closed,but other mixture cuts off engine when closed so it is working.so if anyone can give some insight to what the problems are I'd be grateful.



THANKS

It sounds like it's time for you to disassemble, clean (Stoddard fluid), and rebuild the carburetor. Replace all of the gaskets, including the insulator between the intake manifold and the carburetor.

It sounds like it's time for you to disassemble, clean (Stoddard fluid), and rebuild the carburetor. Replace all of the gaskets, including the insulator between the intake manifold and the carburetor.

I did rebuild the carburetor already,could it also be a vacuum leak someware?

That's why I recommended replacing the insulator between the intake manifold and the carburetor.

That's why I recommended replacing the insulator between the intake manifold and the carburetor.

OK thanks ill give that a try,should I also replace the carb studs?

Shouldn't be necessary.

Gently seat the air mixture screws, to prevent burring them, and back them off 1-1/8 turns. Ensure all other settings are to spec.