Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Check battery voltage with engine off. Then crank engine and run at full throttle and test again. Voltage has to increase by at least one volt! If not, the battery is not being charged. What is the voltage at the diode from the stator? This should be around 14 volts, and should go direct to the battery . Were the magnets in the flywheel intact and not broken? Stator , before the diode should be around 28 volts AC.
Did you find problem with charging system?