1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 93Get this manual
70-75-80-90 (3 cyl (Design 1) Previous body with rubber check valve retainers was colored black
50289 Body (Opposite Side View) Natural Body (Off White) Rubber Valve Cover (Opposite Side View) Plastic Disc Plastic Check Valve Retainer Two Oil Passage Holes Cast Aluminum Cover One Tab Two Tabs