The Namura NA-10001-2K Top End Kit is designed for Honda TRX400FW Foreman 4x4 models from 1995 through 2003. This 86.47 mm bore, +0.50 mm oversize kit features an 11:1 compression ratio and includes the essential components needed for a reliable top-end rebuild: piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit.
Manufactured using Namura’s hypereutectic casting process, the piston provides increased silicon content for controlled expansion and improved wear resistance at elevated cylinder temperatures. The MOS2, or Teflon/Molybdenum, coated skirts are applied using a rolled-on process that creates a durable bond while helping reduce friction, improve heat transfer, and minimize the risk of cold seizures during operation.
The piston also features a machined smooth head to help reflect combustion heat and reduce carbon buildup. Its anodized dome improves heat resistance and durability, offering added protection under demanding riding conditions. These design features support dependable performance and long service life when the cylinder is properly prepared for the +0.50 mm oversize piston.
Fitment includes 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, and 2003 Honda TRX400FW Foreman 4x4 models. Verify the cylinder bore, compression requirements, and model specifications before installation. This kit is supplied by the manufacturer under Namura part number NA-10001-2K.
Features:
- Complete top-end kit: Includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 86.47 mm +0.50 mm oversize: Supports cylinder rebuilding when matched to the properly prepared bore
- 11:1 compression ratio: Designed for the specified Honda TRX400FW Foreman 4x4 application
- MOS2-coated piston skirts: 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 under demanding operating conditions
- Hypereutectic casting process: Provides controlled expansion, added wear resistance, and improved high-temperature capability
- Fitment: Fits 1995–2003 Honda TRX400FW Foreman 4x4 models
- Brand and part number: Namura NA-10001-2K
Fitment:
1995 Honda TRX400FW Foreman 4X4
1996 Honda TRX400FW Foreman 4X4
1997 Honda TRX400FW Foreman 4X4
1998 Honda TRX400FW Foreman 4X4
1999 Honda TRX400FW Foreman 4X4
2000 Honda TRX400FW Foreman 4X4
2001 Honda TRX400FW Foreman 4X4
2002 Honda TRX400FW Foreman 4X4
2003 Honda TRX400FW Foreman 4X4