18-3931 – Piston Ring Set – Johnson / Evinrude

The 18-3931 piston rings offer a reliable replacement ring set for many Johnson / Evinrude outboard engines with a standard bore (2.188"). This set helps restore proper compression and reduce blow-by for better engine performance.

These rings match OEM specifications and suit engines where the original rings are worn, damaged, or missing. Installing a fresh 18-3931 piston ring set ensures tighter cylinder sealing, improved combustion efficiency, and smoother operation.

The 18-3931 piston rings ships as a complete kit — ready to install. It’s ideal for engine rebuilds, overhauls, or maintenance on older outboards. Before ordering, verify your engine’s bore size and part-number compatibility to ensure a correct fit.

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