Performed 100 hour inspection on ENGINE during ANNUAL inspection. Compression: #1 70/80, #2 72/80, #3 72/80, #4 72/80. Drained oil and serviced with 7qts. Phillips 66 100AW oil. Replaced oil filter CH48111-1, cut open old filter and inspected, no metal found. Removed, cleaned, inspected, rotated and reinstalled spark plugs. Removed and replace #1 cylinder exhaust stack with serviceable unit. Checked MAG timing. Work performed in reference to Cessna 172M MM and engine manufacturer OH manual. I certify that this ENGINE was inspected IAW Cessna's 172N ANNUAL inspection checklist and was determined to be in an AIRWORTHY condition.