Namura .020 Over Bore Top End Repair Kit for Yamaha PW50 fits 1990-2024 40.5mm

.020 Over Bore Top End Repair Kit for Yamaha

This top end repair kit, machined .020 oversize to 40.5mm, rebuilds the cylinder and piston assembly for Yamaha PW50 engines, providing a direct replacement for worn OEM components.

Overview

Designed for the Yamaha PW50, this .020 over bore top end repair kit delivers a complete cylinder and piston assembly at 40.5mm. It restores compression and performance in worn engines, making it ideal for ATV and dirt bike maintenance. The kit includes gaskets and rings for a straightforward rebuild.

Built For Performance

• Precision-machined cylinder bore to 40.5mm with .020 overbore
• High-strength cast iron piston ring set for long life
• Forged piston with reinforced wrist pin area
• Complete gasket and seal kit included
• Drop-in replacement for original Yamaha top end

Fits These Machines

• for Yamaha PW50 (1990–2024)

On-The-Job Use

• Restoring top-end power on aged PW50 engines
• Rebuilding after piston seizure or ring failure
• Refreshing an ATV or minibike for recreational riding
• Maintaining consistent compression for teaching new riders

Specs At A Glance

Good To Know

Q: Does this kit include a new cylinder? A: Yes, the kit includes a pre-honed cylinder and piston assembly, along with all necessary gaskets and rings for installation.

Q: Will this work on a 2005 Yamaha PW50? A: Yes, this top end repair kit is designed for Yamaha PW50 models from 1990 to 2024, provided the engine has been bored .020 oversize.

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