39-96170A4 – Piston Ring Set – Mercury

39-96170A4 piston ring set delivers a high-quality replacement ring set designed for Mercury outboard engines. These rings restore compression, reduce blow-by, and help return oil control to engine cylinders that have experienced wear. OEM-spec sizing and proper fit make this set a reliable choice for engine rebuilds or maintenance.

This 39-96170A4 piston ring set is the .030 oversize option, often used when cylinder bores have been re-honed to restore bore integrity. Installing these rings ensures a tight piston-to-cylinder seal, leading to improved combustion efficiency and smoother engine performance. Many Mercury 70–115 HP outboards rely on this ring set for rebuilds or compression restoration after wear.

If your outboard shows signs of low compression, rough idle, or excessive oil consumption — replacing piston rings with the 39-96170A4 set can bring the engine back to factory-spec performance.

Shop at Arizona Outboard Dismantlers to keep your outboard running strong and ready for the water.