Ran engine inflight to normal op temp, hangered, and drained oil. Removed oil filter. Submitted oil sample to Blackstone (46 hrs on oil). Cut open filter and found no debris. Removed and cleaned suction screen and also found no debris. Reinstalled and safety wired suction screen plug. Installed and safety wired new oil filter (Champion CH48110-1). Added 8L oil (Phillips 66 X/C, 20W-50). Removed spark plugs and cleaned plug adapters. No apparent plug fouling observed. Installed new Denso 5347 IKH27 Iridium Power spark plugs (0.030" gap) and copper gasket (Part# M674) using Tempest Anti-Seize (Part# T556) to required torque.
Ran engine at 1500 rpm until CHTs reached 300F. Removed upper plugs. Performed cylinders pressure test and obtained: 1 (78/80), 2 (78/80), 3 (78/80 ), 4 (79/80). Boroscoped each cylinder and stored photos. Nothing notable observed. Reinstalled spark plugs. EGT#1 giving erroneous readings. Replaced with new probe (Alcor #86255 EGT Probe Type K) and ran engine to verify operation.
Pulled prop using newly constructed wooden gantry. Installed new, larger Hartzell 70A alternator (Plane-Power Part No. AL12EI70/B, S No. H-S040586) and belt (Dayco Part No. 15350 ). Also installed 1" blast tube for new alternator. Replaced AC belt. Set belt tension and torqued all bolts to spec. Install new o-ring, reinstalled prop, torqued all bolts to 60 ft-lbs, and safety wired.. Torqued all bolts to specs. Installed new air filter. Inspected all engine compartment connections and components. Ran engine, cycled prop, and confirmed no leaks and normal operation. New W&B calculated.
Lubricated prop with 1oz (6 trigger pulls) of approved grease on each side of hub. Removed wing root fairing and inspected all bolts and harness connections. Removed fuel filters, disassembled, and inspected. No debris found in either one. Found evidence of fuel leak on left side likely due to loose compression fitting aft of the filter. Re-torqued fitting. Removed seat ramp covers and noticed light surface corrosion on floor, probably the result of water intrusion when canopy seal was leaking, since repaired. Re-primed all surfaces below the ramp cover. Removed entire tunnel cover from CB panel to baggage bulkhead and inspected area. Removed floor covers under seats and inspected area. Tightened headset jacks and added lock washer to prevent loosening and tested. Repaired O2 mount. Re-installed baggage area carpet and mounted O2 cylinder. Re-installed all floor plates and carpet.
Updated G3X and G5 software to latest version (9.14) to comply with Garmin Mandatory Service Bulletin 22112 Rev. B, 09Dec22. Re-installed all remaining fairings and cowlings. Test flew the airplane. Return to service.