Namura .040 Over Bore Piston Kit for Yamaha 2002-2018 YZ85 48.5mm

Namura .040 Over Bore Piston Kit for Yamaha

This .040 over bore piston kit provides a 48.5mm piston for Yamaha YZ85 models from 2002 to 2018, restoring engine performance after a cylinder bore.

Overview

This Namura piston kit is an aftermarket .040 over bore piston kit designed for Yamaha YZ85 motorcycles. The piston kit includes a 48.5mm piston, rings, wrist pin, and circlips for a complete top end rebuild. Ideal for maintaining or upgrading your Yamaha YZ85 engine, this piston kit delivers reliable performance.

Built For Performance

• Manufactured from high-silicone aluminum alloy for strength and heat dissipation
• Includes premium piston rings for optimal compression
• CNC-machined wrist pin for precise fit
• Lightweight design reduces reciprocating mass
• Precision-machined to .040 over bore specification
• Kit includes all necessary components for installation

Fits These Machines

• for Yamaha YZ85 (2002-2018)

On-The-Job Use

• Competitive motocross racing
• Trail riding and enduro
• Recreational off-road riding
• Engine rebuilds and top-end overhauls
• High-performance tuning applications

Specs At A Glance

Good To Know

Q: What is the benefit of a .040 over bore piston kit? A: It allows you to refresh a worn cylinder by boring it to a larger size, restoring compression and performance.

Q: Is this kit compatible with stock Yamaha YZ85 pistons? A: This is an aftermarket kit from Namura, not OEM, but designed as a direct replacement for the .040 over bore size.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.