The Namura NX-40097K Top End Kit is designed for 2018–2021 Yamaha YZ65 models and provides the essential components needed for a reliable top-end rebuild. This standard-bore kit includes a piston, piston rings, wrist pin, wrist-pin clips, top-end bearing, and gasket kit. It is engineered for the Yamaha YZ65 43.44 mm standard-bore application with an 11:1 compression ratio, supporting proper fitment and dependable engine performance.
The piston features MOS2, or Teflon/molybdenum, coated skirts applied through a rolled-on process that creates a stronger bond than typical spray-on coatings. This coating helps improve heat transfer, reduce friction, and minimize the risk of cold seizures. Machined smooth heads help reflect combustion heat and reduce carbon buildup, while anodized domes improve heat resistance and durability. The hypereutectic casting process adds silicon to help control expansion, increase wear resistance, and withstand elevated cylinder temperatures.
Designed as a comprehensive replacement solution, the Namura top-end kit helps simplify installation by supplying the major components required for piston replacement in one package. Verify the standard-bore specification, model year, and engine configuration before installation. The NX-40097K fits 2018, 2019, 2020, and 2021 Yamaha YZ65 motorcycles.
Features:
- Fitment: Designed for 2018–2021 Yamaha YZ65 motorcycles
- Kit contents: Includes piston, rings, wrist pin, clips, top-end bearing, and gasket kit
- Bore and compression: Standard-bore 43.44 mm application with an 11:1 compression ratio
- MOS2 coating: Rolled-on Teflon/molybdenum coating helps reduce friction, improve heat transfer, and minimize cold-seizure risk
- Machined smooth head: Helps reflect combustion heat and reduce carbon buildup
- Anodized dome: Increases heat resistance and piston durability
- Hypereutectic construction: Higher silicon content helps reduce expansion and improve wear resistance
Fitment:
2018 Yamaha YZ65
2019 Yamaha YZ65
2020 Yamaha YZ65
2021 Yamaha YZ65