I have a '79 SuperGlide 1200 with a CV carb (replaced the S&S recently). Problem: too rich on idle resulting in fouled plugs. Seems to run good at highway speeds, but the plugs get fouled quickly on idle. Question: What is the best jet size for this carb on this motor?

 

we use 42-45 on applications like yours. Be sure that the float level is correct, if it is too high you will run on the rich side. 1 1/2 turns out on the idle mixture screw. What jets/needle are in it now??