As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ROUGH ENGINE ON RUNUP. MAGNETO REMOVED AND DISASSEMBLED. BEARING CAP ASSEMBLY NOT HELD STATIONARY IN FRAME. RETAINING SCREWS AND TABS WERE FOUND TIGHT BUT NOT TIGHT ON BEARING CAP. BEARINGS FOUND TO BE OK. BELIEVE THAT CAP ON HOUSING WAS MACHINED INCORRECTLY AND WAS NEVER TIGHT FROM DAY ONE.