As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PILOT REPORTED FAILURE OF ENGINE TO MAINTAIN FULL POWER AT THE TAKEOFF SETTING. AIRCRAFT RETURNED TO THE RAMP. COMPRESSION TEST REVEALED CYLINDER NR 7, WAS LOW ON COMPRESSION AND LEAKING VIA A CRACK IN THE EXHAUST PORT AREA OF THE CYLINDER. THE OFFENDING CYLINDER WAS REMOVED AND AN OVERHAULED CYLINDER WAS INSTALLED. AIRCRAFT RETURNED TO FLIGHT STATUS. (TC NR 20071029003)