I've been having problems with the car "bucking" when it's going up hills and, recently, it has also over-heated, idled low and died on startup. My mechanic has narrowed it down to the carburetor and a friend thinks it might be the flow valve on the carburetor that controls the air flow coming in.

Question:
Does anyone know what this part is specifically called and how difficult is this to replace myself? Can I find this piece in a carb rebuild kit?

I always thought it was like a spinner type piece, but the rebuild kits only seem to have flat sheet type pieces.

Its basically a flap that will close air flow on top and depending a couple venturies and metering block etc. you'd be better off getting a price of a rebuild by the mechanic first because it will take time and diligence to rebuild one, its not fun either and he'll have to chemically soak it in cleaning solution, I did mine once and it is not fun.