Y2K said:
That could also be an air leak leaning out the mixture.
I agree. The ignition module will not cause idle speed problems, but an air leak will. To check for the leak, start the engine and spray some WD-40 (using the 4 inch red "nozzle") that comes with the can, and spray it around anywhere there might be a leak. If the engine speed drops off slightly, then you have a leak. Some people use brake cleaner to raise the rpm, but that can be very dangerous since brake cleaner is VERY flammable! One mistake and you won't have any facial hair left (and maybe no skin left, either).
Remove your carb and intake manifold and replace the seals. When doing this, hold the intake against the heads without the gaskets first, to check alignment. The flanges should be flush with no large gaps. If there is a gap, you'll have to loosen the affected head and rotate it slightly so the intake will seal properly. I usually do this during assembly so I don't have to worry about it later.
One more thing.... make sure you tighten all the fasteners a little at a time during installation. If you completely tighten one flange first, then it might pull the others out of alignment. It's best to connect the intake to the heads BEFORE attaching the carb. That way you can look into the intake to check for gaps between the heads and manifold.
Once you get everything sealed up good and tight, throw it on a dyno and get it tuned properly. You should be ok after that. I'm still wondering about the black fuel, though. Oil should NOT be getting into your fuel. Maybe bad gas in the tank?????
Good luck! :thumbsup: