The Namura NA-40019-2K Top End Kit is designed for Yamaha YFM125G Grizzly all-terrain vehicles from 2004 through 2013. This 49.5 mm +0.50 mm oversize kit features an 11:1 compression ratio and includes the piston, piston rings, wrist pin, retaining clips, top end bearing, and gasket kit needed for a complete top-end service. It is manufactured by Namura and supplied under vendor part number NA-40019-2K.
Feature: MOS2 (Teflon/Molybdenum) coated skirts use a rolled-on application process that creates a bond up to 10 times stronger than many spray-on coatings. The coating helps improve heat transfer, reduce friction, and minimize the risk of cold seizures. Feature: Machined smooth heads reflect combustion heat and help reduce carbon buildup, protecting the piston crown while supporting efficient engine operation.
Feature: Anodized domes improve heat resistance and durability, with increased strength compared with non-anodized piston domes. Feature: The hypereutectic casting process adds silicon for controlled expansion, enhanced wear resistance, and improved durability at higher cylinder temperatures. The included components make this kit suitable for rebuilding the top end of compatible Yamaha Grizzly engines when cylinder preparation matches the specified oversize piston.
Fitment includes 2004-2013 Yamaha YFM125G Grizzly models with SRA suspension. Confirm the vehicle model, year, cylinder condition, and required oversize before installation. Professional installation is recommended, including proper piston ring gap, piston orientation, torque specifications, and gasket sealing procedures.
Features:
- Complete top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 49.5 mm +0.50 mm oversize 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 head helps reflect combustion heat and reduce carbon buildup
- Anodized dome improves heat resistance and piston durability
- Hypereutectic casting provides controlled expansion and enhanced wear resistance
- Fits 2004-2013 Yamaha YFM125G Grizzly models with SRA suspension
- Brand: Namura
- Manufacturer: Namura
- Vendor part number: NA-40019-2K
Fitment:
1989 Yamaha YFA1 Breeze 125
1990 Yamaha YFA1 Breeze 125
1991 Yamaha YFA1 Breeze 125
1992 Yamaha YFA1 Breeze 125
1993 Yamaha YFA1 Breeze 125
1994 Yamaha YFA1 Breeze 125
1995 Yamaha YFA1 Breeze 125
1996 Yamaha YFA1 Breeze 125
1997 Yamaha YFA1 Breeze 125
1998 Yamaha YFA1 Breeze 125
1999 Yamaha YFA1 Breeze 125
2000 Yamaha YFA1 Breeze 125
2001 Yamaha YFA1 Breeze 125
2002 Yamaha YFA1 Breeze 125
2003 Yamaha YFA1 Breeze 125
2004 Yamaha YFA1 Breeze 125
2004 Yamaha YFM125G Grizzly [SRA]
2005 Yamaha YFM125G Grizzly [SRA]
2006 Yamaha YFM125G Grizzly [SRA]
2007 Yamaha YFM125G Grizzly [SRA]
2008 Yamaha YFM125G Grizzly [SRA]
2009 Yamaha YFM125G Grizzly [SRA]
2010 Yamaha YFM125G Grizzly [SRA]
2011 Yamaha YFM125G Grizzly [SRA]
2012 Yamaha YFM125G Grizzly [SRA]
2013 Yamaha YFM125G Grizzly [SRA]