Namura Size C Standard Bore Top End Repair Kit for Yamaha YZ250 2002-2024 66.4mm

Size C Standard Bore Top End Repair Kit for Yamaha YZ250

This top end repair kit includes a piston, rings, and gaskets for rebuilding the cylinder on a Yamaha YZ250 with a 66.4mm bore.

Overview

This Size C Standard Bore Top End Repair Kit is a complete set of components to refresh the upper cylinder on a Yamaha YZ250 from 2002 to 2024. The kit contains a 66.4mm piston, rings, wrist pin, and gaskets to restore compression and performance. Designed for off-road racing, this top end repair kit delivers reliable power and durability.

Built For Performance

• 66.4mm bore piston matched to cylinder tolerance
• High-strength rings for consistent seal
• Includes head gasket, base gasket, and exhaust gasket
• Precision-machined wrist pin with circlips
• Tested for wear resistance in high-RPM environments

Fits These Machines

• for Yamaha YZ250 2002-2024

On-The-Job Use

• Motocross racing and trail riding on Yamaha YZ250
• Rebuilding top end after wear or piston failure
• Competition and recreational off-road use

Specs At A Glance

Good To Know

Q: Does this kit include the cylinder? A: No, this top end repair kit includes only the piston assembly and gaskets; the cylinder must be inspected and reused or replaced separately.

Q: Can I use this kit for a 2001 model? A: This kit is specifically for 2002-2024 Yamaha YZ250 models; earlier years may have different cylinder dimensions.

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