Restore top-end performance with the NAMURA NA-10000-4K Top End Kit, designed for select Honda TRX450 Foreman ES and Foreman S models. This 90.96 mm, +1.00 mm overbore 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 comprehensive cylinder rebuild. It is engineered for dependable fitment and durable performance in properly prepared applications.
Feature: MOS2 (Teflon/Molybdenum) coated piston skirts use a rolled-on application process that creates a bond significantly stronger than typical spray-on coatings. The coating supports improved heat transfer, reduced friction, and added protection against cold seizure conditions. Machined smooth piston heads help reflect combustion heat and reduce carbon buildup, helping protect the piston crown during operation.
Feature: Anodized piston domes improve heat resistance and durability, while the hypereutectic casting process increases silicon content to help control expansion, improve wear resistance, and withstand higher cylinder temperatures. These design elements make the NAMURA top-end assembly a practical choice for rebuilding or refreshing a worn Honda ATV engine.
Fitment includes 1998–2004 Honda TRX450FE Foreman ES with SRA and 1998–2000 Honda TRX450FM Foreman S with SRA. Confirm the vehicle model, year, cylinder condition, and required overbore specification before installation. The manufacturer part number is NA-10000-4K, and the vendor part number is 186-10004.
Features:
- Top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
- 90.96 mm piston diameter with a +1.00 mm overbore and 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 dome improves heat resistance and piston durability
- Hypereutectic casting process provides controlled expansion, increased wear resistance, and improved high-temperature performance
- Fits 1998–2004 Honda TRX450FE Foreman ES SRA models
- Fits 1998–2000 Honda TRX450FM Foreman S SRA models
- Brand: NAMURA
- Manufacturer part number: NA-10000-4K
- Vendor part number: 186-10004
Fitment:
1998 Honda TRX450FE Foreman ES [SRA]
1998 Honda TRX450FM Foreman S [SRA]
1999 Honda TRX450FE Foreman ES [SRA]
1999 Honda TRX450FM Foreman S [SRA]
2000 Honda TRX450FE Foreman ES [SRA]
2000 Honda TRX450FM Foreman S [SRA]
2001 Honda TRX450FE Foreman ES [SRA]
2001 Honda TRX450FM Foreman S [SRA]
2002 Honda TRX450FE Foreman ES [SRA]
2002 Honda TRX450FM Foreman S [SRA]
2003 Honda TRX450FE Foreman ES [SRA]
2003 Honda TRX450FM Foreman S [SRA]
2004 Honda TRX450FE Foreman ES [SRA]
2004 Honda TRX450FM Foreman S [SRA]