Restore dependable engine performance with the Namura NA-40019K Top End Kit, designed for 2004–2013 Yamaha YFM125G Grizzly models with SRA suspension. This 49.00 mm standard-bore kit features 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 Namura piston uses a MOS2 coating made from Teflon and molybdenum. Its rolled-on application creates a durable bond designed to help improve heat transfer, reduce friction, and minimize the risk of cold seizures. The machined smooth head helps reflect combustion heat and limit carbon buildup, supporting piston protection and consistent engine operation.
For added durability, the piston dome is anodized to improve heat resistance and strength. The hypereutectic casting process increases silicon content to help control expansion, improve wear resistance, and withstand elevated cylinder temperatures. These features make the NA-40019K a practical replacement solution for maintaining reliable performance in compatible Yamaha utility ATV engines.
Fitment: Fits 2004–2013 Yamaha YFM125G Grizzly models with SRA suspension. Verify the model year, engine configuration, and standard-bore specification before installation. Manufacturer part number: NA-40019K. Vendor part number: 186-4019.
Features:
- Complete top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 49.00 mm standard-bore piston with an 11:1 compression ratio
- MOS2 Teflon and molybdenum coated skirt helps 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 improved high-temperature performance
- Fits 2004–2013 Yamaha YFM125G Grizzly models with SRA suspension
- Brand: Namura; manufacturer part number: NA-40019K; vendor part number: 186-4019
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]