My carb seems to run rich from idle to WOT. Theres a strong exhaust smell, hesitation off idle to WOT, black smoke, etc..

My question is, what can I do about this???? I'm just learning about carbs and don't really know what to do..

When I bought the car it already had an remanufactured M4ME, I dont know for what application though.

The mixture screws only control the idle mixture right?

 

Dolph,

Yes, the mixture control screws only adjust the idle/transfer port mixture rates. The main circuit mixture is controlled by the main jet sizes and fuel level in the bowl (float adjustment). WOT mixture is controlled by the power valve size, secondary air valve (AV) spring rate, secondary metering rod/jet sizes, and the cam that positions those metering rods.

Another thing to be aware of on Rochester Quads is the pressed in plugs on the underside of the main metering wells can leak, creating an overall rich condition. You may be able to compensate for that soemwhat at idle by the mixture screws, but at part and full throttle operation, there will be no easy adjustments. Ususally any leakage from these plugs will cause hard starting due to flooding. If you are starting easily (without extended cranking times) the chance is that the float adjustment is off.