Namura NX-10025K Top End Kit for Honda CR250R, 66.34 mm Standard Bore, 8.5:1 Compression

Restore reliable top-end performance with the Namura NX-10025K Top End Kit, designed for Honda CR250R models equipped with a Nikasil cylinder. This complete kit includes a piston, piston rings, wrist pin, retaining clips, top-end bearing, and gasket kit, providing the essential components needed for a thorough top-end rebuild. The standard-bore piston measures approximately 2.61 inches and is designed for an 8.5:1 compression ratio.

The Namura piston uses a hypereutectic casting process that increases silicon content for reduced expansion, improved wear resistance, and reliable performance under elevated cylinder temperatures. MOS2, or Teflon and molybdenum, coated skirts use a rolled-on application process that creates a bond claimed to be 10 times stronger than spray-on coatings. This coating helps improve heat transfer, reduce friction, and minimize the risk of cold seizures during operation.

Additional piston features include a machined smooth head that helps reflect combustion heat and reduce carbon buildup, along with an anodized dome engineered to improve heat resistance and durability. These design elements help protect the piston crown and support consistent performance. The Namura NX-10025K is a direct-fit top-end solution for select Honda CR250R applications from 1997 through 2001. Verify the cylinder condition, bore specification, and model year before installation.

Features:

• Complete top-end kit includes piston, rings, wrist pin, retaining clips, top-end bearing, and gasket kit
• Standard-bore piston measures 66.34 mm, approximately 2.61 inches, and supports an 8.5:1 compression ratio
• MOS2 Teflon and 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 improves heat resistance and durability
• Hypereutectic casting process provides reduced expansion, increased wear resistance, and improved high-temperature performance
• Fits 1997, 1998, 1999, 2000, and 2001 Honda CR250R models with a Nikasil cylinder
• Brand: Namura
• Manufacturer part number: NX-10025K
• Vendor part number: 185-1025