Description
When your Honda 420 four-stroke demands a full refresh, settling for anything less than a complete, matched top-end kit leaves performance on the table. The WSM Top End Kit eliminates guesswork by supplying precision-engineered pistons, rings, and gaskets engineered to work together as a system—ensuring proper ring seating, optimized compression, and reliable longevity. Whether you’re rebuilding after high-mileage wear or preparing for a season of hard racing, this kit delivers the OEM-quality components you need in one complete package.
- Includes pistons and rings
- Piston pins and clips
- Needle bearings
- Head gasket
- Base gasket
- Intake gasket
- Exhaust gasket
- Oil filter
- .75mm oversize specification
- Honda 420 four-stroke fitment
- MPN: 54-231-23
- Bolt-on installation








