I have a 91' Heritage. The bike will idle, but when I try to accelerate I lose power and it starts to backfire and pop thru the carb. When I let off the gas it idles fine. I have noticed when this happens I lose some power to the system. I have cleaned the carb. Relaced the voltage regulator, ignition module and starter relay. Sometimes I will lose all power and it will not come back on for about 1 minute but then starts ok. Help!