The Namura NA-50006-2K Top End Kit is designed for select Polaris 90cc ATV applications requiring a 52.46 mm (+0.50 mm) piston and an 11:1 compression ratio. This complete kit includes the piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit for a convenient engine refresh. The kit fits the 2001–2006 Polaris Sportsman 90 and the 2003–2006 Polaris Predator 90.
The piston is manufactured using a hypereutectic casting process that increases silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. Its MOS2, or Teflon/molybdenum, coated skirts are applied using a rolled-on process that creates a strong bond while helping reduce friction, improve heat transfer, and minimize the risk of cold seizures. These features support reliable performance during demanding ATV use.
Additional piston construction features include a machined smooth head that helps reflect combustion heat and reduce carbon buildup, along with an anodized dome engineered for improved heat resistance and durability. The Namura NA-50006-2K is intended for properly prepared engines using the specified oversize bore and should be verified against the existing cylinder, compression requirements, and engine condition before installation. Manufacturer part number: NA-50006-2K. Vendor part number: 186-50062.
Features:
- Complete top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 52.46 mm (+0.50 mm) piston size with an 11:1 compression ratio
- MOS2 Teflon/molybdenum-coated piston skirts help reduce friction, improve heat transfer, and minimize cold-seizure risk
- Machined smooth piston head helps reflect combustion heat and reduce carbon buildup
- Anodized piston dome improves heat resistance and durability
- Hypereutectic casting process provides controlled expansion, enhanced wear resistance, and increased high-temperature durability
- Fits 2001–2006 Polaris Sportsman 90 models
- Fits 2003–2006 Polaris Predator 90 models
- Brand: Namura
- Manufacturer part number: NA-50006-2K
- Vendor part number: 186-50062
Fitment:
2001 Polaris Sportsman 90
2002 Polaris Sportsman 90
2003 Polaris Predator 90
2003 Polaris Sportsman 90
2004 Polaris Predator 90
2004 Polaris Sportsman 90
2005 Polaris Predator 90
2005 Polaris Sportsman 90
2006 Polaris Predator 90
2006 Polaris Sportsman 90