Performed 100hr/Annual inspection on ENGINE. Compressions #1: 66/80, #2: 72/80, #3: 62/80, #4: 72/80. Removed, cleaned, inspected, tested, and gapped spark plugs to spec. Removed, cut open and inspected oil filter. No defects found. Drained oil and serviced with 7qts. Aeroshell W100 Plus. Lubricated controls. De-greased engine. Re-secured alternator belt. All work done in reference to Cessna 172 MM, Lycoming Overhaul Manual, AC 43.13-B. I certify this Engine was inspected in reference to Cessna 172 100hr/Annual inspection checklist and has been found to be in an airworthy condition. Engine is approved for RTS at this time. LYCOMING O-320-E2D S/N: L-34839-27A