39-16055A5 Piston Ring Kit 0.5 mm – Mercury

The 39-16055A5 Piston Ring Kit is a genuine Mercury OEM part that provides a precise 0.5 mm oversize bore fit. It ensures proper compression and engine performance when worn cylinders exceed standard tolerances.

This kit directly replaces part number 39‑16055A5 and was superseded by 8M0080348, offering full interchangeability and smooth installation. Mercury designed this kit for engines with slight bore wear, preserving head gasket integrity and avoiding costly repairs.

Made to OEM standards, the ring set delivers tight sealing and long-lasting durability. Mercury Marine built it from high-grade materials to withstand heat, pressure, and the demanding marine environment.

Key Features:

• OEM quality – exact engineering for full compatibility

• Oversize bore – +0.5 mm to restore compression

• Supersedes – 39‑16055A5, replaced by 8M0080348

• Materials – marine-grade alloys for corrosion resistance

• Purpose – ideal for engines with worn cylinders needing a standard rebuild

At Arizona Outboard Dismantlers, we specialize in genuine and aftermarket marine parts that keep you on the water. The 39-16055A5 Piston Ring Kit delivers factory-spec compression and helps your engine run smoothly.