As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AUS) LH ENGINE LH MAGNETO IMPULSE COUPLING SPRING BROKEN - ENGINE HAD NOT OPERATED FOR APPROXIMATELY 8 MONTHS WHILE AIRCRAFT WAS WAITING FOR FITMENT OF THE RH ENGINE - ENGINE WAS GROUND RUN ON AWEEKLY BASIS - SUSPECT CORROSION AS CAUSE OF FAILURE