Namura Standard Bore Piston Kit Size C for Yamaha YZ250F & WR250F 2001-2004 77mm

Namura Standard Bore Piston Kit Size C for Yamaha

This Namura standard bore piston kit is a direct replacement for Yamaha YZ250F and WR250F models from 2001 to 2004, featuring a 77mm bore size (size C) for rebuilding top-end performance.

Overview

This standard bore piston kit includes a forged piston, rings, wrist pin, and circlips, designed to restore compression in Yamaha 250F engines. The Size C (77mm) variant matches OEM specifications for these generations. It is intended for recreational and competition use, providing reliable power delivery.

Built For Performance

• Forged aluminum construction for strength and heat dissipation
• Precision-machined ring grooves for consistent sealing
• Includes a wrist pin with hardened surface for reduced wear
• Compatible with standard bore cylinders requiring no oversizing
• Each kit includes circlips for secure pin retention

Fits These Machines

• for Yamaha YZ250F (2001-2004)
• for Yamaha WR250F (2001-2004)

On-The-Job Use

• Rebuilding top-end on dirt bikes after hours of use
• Replacing worn pistons during routine engine maintenance
• Used in motocross and trail riding applications
• Restoring lost compression and engine power

Specs At A Glance

Good To Know

Q: Is this piston kit for a 77mm standard bore? A: Yes, this is the Size C standard bore piston at 77mm, suitable for cylinders that have not been oversized.

Q: Will this fit a 2003 YZ250F? A: This kit is designed for 2001-2004 Yamaha YZ250F and WR250F models; confirm your engine serial number for exact fit.

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