The Namura NA-40007-2K Top End Kit is designed for Yamaha XT600 models from 1984 through 1993. This 95.5 mm +0.50 oversize kit with an 11:1 compression ratio provides the essential components needed for a reliable top-end rebuild, including a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit. Verify cylinder condition and required oversize specifications before installation.
The piston uses Namura’s hypereutectic casting process to increase silicon content, helping reduce expansion while improving wear resistance and performance in high-temperature cylinder environments. Its MOS2, or Teflon/Molybdenum, coated skirts are applied using a rolled-on process that creates a strong bonded surface. 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 on the piston crown, supporting protection of the top end. The anodized dome improves heat resistance and durability, while offering greater strength than a non-anodized piston dome. Together, these features support dependable operation for street, touring, and off-road applications when installed with the correct clearances and service procedures.
Manufacturer part number: NA-40007-2K. Vendor part number: 186-40072. The kit fits 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, and 1993 Yamaha XT600 motorcycles. Always compare the existing piston, cylinder bore, compression ratio, and gasket configuration with the vehicle’s service requirements before ordering.
Features:
- Application: Top-end rebuild kit for 1984–1993 Yamaha XT600 models
- Kit Contents: Includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- Piston Size: 95.5 mm +0.50 oversize with an 11:1 compression ratio
- Skirt Coating: MOS2 Teflon/Molybdenum coating helps reduce friction, improve heat transfer, and minimize cold-seizure risk
- Piston Design: Machined smooth head helps reflect combustion heat and reduce carbon buildup
- Dome Treatment: Anodized dome improves heat resistance and durability
- Casting Process: Hypereutectic construction supports reduced expansion and improved wear resistance
- Brand: Namura
- Manufacturer Part Number: NA-40007-2K
- Vendor Part Number: 186-40072
Fitment:
1984 Yamaha XT600
1985 Yamaha XT600
1986 Yamaha XT600
1987 Yamaha XT600
1988 Yamaha XT600
1989 Yamaha XT600
1990 Yamaha XT600
1991 Yamaha XT600
1992 Yamaha XT600
1993 Yamaha XT600
1994 Yamaha XT600
1995 Yamaha XT600
1998 Yamaha YFM600FG Grizzly 4WD [SRA]
1999 Yamaha YFM600FG Grizzly 4WD [SRA]
2000 Yamaha YFM600FG Grizzly 4WD [SRA]
2001 Yamaha YFM600FG Grizzly 4WD [SRA]