Performed 100 hour/ANNUAL inspection on engine. Compression check: #1-70/80, #2-78/80, #3-75/80, #4-78/80. Drained oil and refilled with 7 quarts Aeroshell W100 plus oil. R&R oil filter with new CH48111-1. Cut and inspected old filter, no metal found. Replaced #1 intake gasket P/N-71973. Removed, cleaned, inspected, gaped, tested, and rotated spark plugs, replaced #3 top plug with new UREM 40E. Work done in reference to Cessna 172 MM, IPC, and FAR 43 app d. I certify that this engine was inspected in reference to Cessna 172 100 hour/ANNUAL inspection checklist and was found to be in an airworthy condition and is approved for return to service at this time.