Sierra 18-7913 Oil Filter

A four stroke oil filter built for salt air rather than a parking garage. The canister is heavy wall steel with an epoxy coating, because the failure mode on a marine filter is not the media, it is the can rusting through from the outside while the boat sits on a lift.

• Thread specification 20 mm x 1.5
• Fits Mercury 8 and 9.9 HP (323cc), 15 and 20 HP carbureted, and 25 and 30 HP EFI from model year 2006 and newer
• Fits Mercury 25 and 30 HP EFI four strokes, 2006 and up, s/n OT801000 and up with the 498/492cc block
• Also interchanges with several Honda outboard filter numbers
• Anti-drain-back valve, epoxy coated heavy wall steel canister

Change oil and filter at the end of the season rather than the start. Acid and moisture in used oil do their damage while the boat sits.