As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ENGINE RUN-UP FOR TAKEOFF, ENGINE QUIT. INVESTIGATION BY BORESCOPE FOUND NR 4 CYLINDER EXHAUST VALVE NOT WORKING. REMOVED ROCKER BOSS AND FOUND EXHAUST VALVE ROCKER SHAFT INBOARD ROCKER BOSS CASTING AND COVER TAB FAILED. OUTBOARD CASTING OK. ALL OTHER CYLINDERS ROCKER CASTINGS OK. SUSPECT ROCKER RETAIN CLIP FAILED INITIALLY.