Restore top-end performance with the NAMURA NA-50025-2K Top End Kit, featuring a 78.95 mm piston with a +0.50 mm oversize specification and an 11:1 compression ratio. Designed for select Polaris 330 engines, this complete kit includes the piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit for a comprehensive engine rebuild.
The piston uses NAMURA’s hypereutectic casting process to provide increased silicon content, controlled expansion, and improved wear resistance under elevated cylinder temperatures. Its MOS2 Teflon/molybdenum-coated skirts use a rolled-on application process that creates a durable bond while helping reduce friction, improve heat transfer, and minimize the risk of cold seizures. Machined smooth heads help reflect combustion heat and reduce carbon buildup, while the anodized dome improves heat resistance and durability.
This top-end kit fits 2008–2013 Polaris Trail Blazer 330 models and 2003–2006 Polaris Trail Boss 330 models. Verify the engine model, bore specification, and required oversize before installation. The kit is manufactured by NAMURA and supplied under manufacturer and vendor part number NA-50025-2K.
Features:
- Complete top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 78.95 mm piston with +0.50 mm oversize specification and 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 increases heat resistance and durability
- Hypereutectic casting process provides controlled expansion and improved wear resistance
- Fits 2008–2013 Polaris Trail Blazer 330 and 2003–2006 Polaris Trail Boss 330
- Brand: NAMURA; Manufacturer and vendor part number: NA-50025-2K
Fitment:
2003 Polaris Magnum 330 2X4
2003 Polaris Magnum 330 4X4
2003 Polaris Trail Boss 330
2004 Polaris Atp 330
2004 Polaris Magnum 330 2X4
2004 Polaris Magnum 330 4X4
2004 Polaris Trail Boss 330
2005 Polaris Atp 330
2005 Polaris Magnum 330 2X4
2005 Polaris Magnum 330 4X4
2005 Polaris Trail Boss 330
2006 Polaris Magnum 330 4X4
2006 Polaris Trail Boss 330
2007 Polaris Trail Boss 330
2008 Polaris Trail Blazer 330
2008 Polaris Trail Boss 330
2009 Polaris Trail Blazer 330
2009 Polaris Trail Boss 330
2010 Polaris Trail Blazer 330
2010 Polaris Trail Boss 330
2011 Polaris Trail Blazer 330
2011 Polaris Trail Boss 330
2012 Polaris Trail Blazer 330
2012 Polaris Trail Boss 330
2013 Polaris Trail Blazer 330
2013 Polaris Trail Boss 330