Restore top-end performance with the NAMURA NA-50080K1 Top End Kit, designed for select Polaris Ranger 800 models. This standard-size kit features a 79.95 mm piston with an 11:1 compression ratio and includes the essential components needed for a complete top-end rebuild: piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit. The kit is manufactured for dependable fitment and service in compatible Polaris utility vehicles.
The piston uses a hypereutectic casting process to provide increased silicon content, controlled expansion, and improved wear resistance under elevated cylinder temperatures. Its MOS2, or Teflon/Molybdenum, coated skirts are applied using a rolled-on process for a durable bond. This coating helps reduce friction, improve heat transfer, and minimize the risk of cold seizures during operation. Machined smooth heads help reflect combustion heat and reduce carbon buildup, supporting piston protection and consistent engine performance.
Anodized domes add heat resistance and durability for demanding riding and utility applications. The NAMURA NA-50080K1 Top End Kit fits 2013–2014 Polaris Ranger 800 4x4 Midsize models, 2011–2014 Polaris Ranger Crew 800 4x4 models, and 2011–2014 Polaris Ranger 800 6X6 models. Verify the vehicle year, model, engine configuration, and standard bore application before installation. This product is identified by manufacturer part number NA-50080K1 and vendor part number 186-50801.
Features:
- Complete top-end kit includes piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- Standard-size 79.95 mm piston with an 11:1 compression ratio
- MOS2 Teflon/Molybdenum-coated 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 increases heat resistance and durability
- Hypereutectic casting process provides controlled expansion and increased wear resistance
- Fits select 2011–2014 Polaris Ranger 800 4x4 Midsize, Ranger Crew 800 4x4, and Ranger 800 6X6 models
- Brand: NAMURA
- Manufacturer part number: NA-50080K1
- Vendor part number: 186-50801
Fitment:
2011 Polaris Ranger 800 4x4
2011 Polaris Ranger 800 6X6
2011 Polaris Ranger Crew 800 4x4
2012 Polaris Ranger 800 6X6
2012 Polaris Ranger Crew 800 4x4
2013 Polaris Ranger 800 4x4
2013 Polaris Ranger 800 4x4 [Midsize]
2013 Polaris Ranger 800 6X6
2013 Polaris Ranger Crew 800 4x4
2014 Polaris Ranger 800 4x4
2014 Polaris Ranger 800 4x4 [Midsize]
2014 Polaris Ranger 800 6X6
2014 Polaris Ranger Crew 800 4x4
2016 Polaris Ranger 800 6X6