As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT EXPERIENCED POWER LOSS SHORTLY AFTER TAKE OFF AND LANDED AS SOON AS POSSIBLE. UPON REMOVAL OF SPARK PLUGS THERE WAS UNUSUAL FOULING ON CYLINDER #1 BOTTOM SPARK PLUG, LOOKING THROUGH THE SPARK PLUG HOLE OF CYLINDER #1 REVEALED A HOLE BLOWN THROUGH THE PISTON.