As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WOULD NOT START. FOUND IMPULSE COUPLING WOULD NOT ENGAGE AT ALL TIMES. FOUND EXCESSIVE WEAR ON TOE OF FLYWEIGHTS WHICH WOULD NOT ALLOW COUPLING TO ENGAGE TOP PINS. NO WEAR NOTED ON PINS. INSPECTION PER TCM BULLETIN WOULD HAVE INDICATED AN AIRWORTHY COUPLING. THIS COUPLING IS THE NEW STYLE SNAP RING STYLE.