runrz,
Once you've checked the dizzy as SWEET and Drew say, and assuming it's behaving, you might try a new condenser. I had similar issues as you, covered
here. It was like someone reached into the cab and turned the ignition to the off position every now and then. I checked with a multimeter to confirm that the voltage dropped clean out when this happened.
I'd make sure and listen to Red58 and Sweet closely as they are experts on this engine, but if all else fails, try swapping out the condenser later and see if it helps.
Good Luck,
Jim
