PISTON KIT 40mm 1981-2021 YAMAHA PW50 18U-11631-00-A0

This piston kit is a standard replacement designed for the Yamaha PW50 and various Yamaha 50cc models from 1979 to 2021. It provides precise fitment and durability for small two-stroke engines, matching or exceeding OEM specifications.

Features

• Constructed from high-tech materials for long-lasting performance and reliability


• Elliptically designed for consistent bearing surface under thermal expansion


• Direct OEM replacement for easy installation


• Includes all necessary components for complete piston replacement


• Manufactured to meet or exceed OEM quality standards

Specifications

• Piston Diameter: 40mm


• Piston Height: 50mm


• Piston Pin Length: 33mm (1.29")


• Piston Pin Outer Diameter: 10mm

Package Included

• 1 x Piston


• 2 x Piston Rings


• 1 x Piston Pin


• 1 x Small End Bearing


• 2 x Circlips

Cross-Reference OEM Part Numbers

• PROX 01.2005.000


• Piston (Std): 18U-11631-00-A0, 4J2-11631-00-A0


• Piston Pin: 3L5-11633-00-00


• Piston Ring Set (Std): 260-11610-04-00, 260-11601-03-00


• Circlip: 93450-11021-00

Vehicle Fitments

• Yamaha PW50 (1981–2021)


• 1982 MJ50J


• 1979 QT50F


• 1980 LC50G


• 1980 QT50, QT502G, QT50G


• 1981 PW50H, QT50H


• 1982 PW50J, QT50J


• 1983 PW50K, QT50K


• 1984 YAMAHOPPER (QT50L)


• 1985 Y-ZINGER (PW50N), YAMAHOPPER (QT50N)


• 1986 Y-ZINGER (PW50S), YAMAHOPPER (QT50S)


• 1987 Y-ZINGER (PW50T), YAMAHOPPER (QT50T)


• 1990–2021 Y-ZINGER / PW50 (PW50A to PW50M2, including all suffix variants)