The Namura NA-10040-2K Top End Kit is a complete replacement solution for select Honda Rancher AT models. Designed with an 85.47 mm piston size and an 11:1 compression ratio, this +0.50 mm kit includes the piston, piston rings, wrist pin, retaining clips, top end bearing, and gasket kit needed for a dependable top-end rebuild.
Engineered for durability and performance, the Namura piston uses a hypereutectic casting process with increased silicon content to help reduce expansion, improve wear resistance, and withstand elevated cylinder temperatures. The MOS2 Teflon/molybdenum-coated skirts use a rolled-on application process that creates a strong 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 Namura top end kit fits 2004–2007 Honda TRX400FA Rancher AT models with SRA and 2004–2007 Honda TRX400FGA Rancher AT GPScape models with SRA. Verify the model designation, year, bore requirement, and engine specifications before installation. Manufacturer part number: NA-10040-2K. Vendor part number: 186-10402.
Features:
- Complete top end kit includes piston, rings, wrist pin, retaining clips, top end bearing, and gasket kit
- 85.47 mm piston size with +0.50 mm oversize and an 11:1 compression ratio
- MOS2 Teflon/molybdenum-coated 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 reduced expansion, improved wear resistance, and increased high-temperature capability
- Fits 2004–2007 Honda TRX400FA Rancher AT models with SRA
- Fits 2004–2007 Honda TRX400FGA Rancher AT GPScape models with SRA
- Brand: Namura
- Manufacturer part number: NA-10040-2K
- Vendor part number: 186-10402
Fitment:
2004 Honda TRX400FA Rancher AT [SRA]
2004 Honda TRX400FGA Rancher AT GPScape [SRA]
2005 Honda TRX400FA Rancher AT [SRA]
2005 Honda TRX400FGA Rancher AT GPScape [SRA]
2006 Honda TRX400FA Rancher AT [SRA]
2006 Honda TRX400FGA Rancher AT GPScape [SRA]
2007 Honda TRX400FA Rancher AT [SRA]
2007 Honda TRX400FGA Rancher AT GPScape [SRA]