Motorcycle Repair: Strange spark plug problem, fuel air mixture, point gap

Question
Hi Mike,

Thanks very much for the informed response. When I rebuilt the bike, I cleaned the carbs and did a tune up (i.e.-new points and condenser), so I think the reason that the plugs are fouling must be that I am running it too rich. The plugs are jet black. I know that they are supposed to be a coffee color, but I'm not sure of the exact procedure for adjusting the fuel/air mixture. Could you point me in the right direction. Hopefully, if i do that, it will solve the problem. Thanks!
~Rob Drew

Answer
Rob,
 That is really a trial and error process however, you should start at the common setting of 1 and 1/2 turns out from seated.  Be sure the plug is the middle heat range (not one over or below) and that it is gapped correctly.  Also be positive you are timed correctly and the point gap it correct.  Also, be sure your oil to fuel ratio is not too extreme.  A moderate level of bluish smoke is normal, big clouds is not.

Hope this helps,
Mike