Namura NX-10026-BK 66.35 mm Top End Kit for 1986-1991 Honda CR250R

The Namura NX-10026-BK Top End Kit is designed for Honda CR250R models from 1986 through 1991 equipped with a Nikasil cylinder. This complete kit includes a piston, piston rings, wrist pin, wrist pin clips, top-end bearing, and gasket kit for a convenient top-end rebuild. The 66.35 mm piston size and 8.5:1 compression configuration are suited to the specified Honda CR250R applications, helping restore reliable engine performance and proper fitment.

Namura uses a hypereutectic casting process to increase silicon content, reduce expansion, improve wear resistance, and support operation at elevated cylinder temperatures. The piston skirts feature a rolled-on MOS2 coating made from Teflon and molybdenum. This bonded coating is engineered to reduce friction, improve heat transfer, and help minimize the risk of cold seizures during engine operation.

The piston also features machined smooth heads to reflect combustion heat and help reduce carbon buildup. Anodized domes provide increased heat resistance and durability compared with standard non-anodized piston designs. The included components are selected to support a complete top-end service, making this Namura kit a practical replacement solution for compatible Honda two-stroke engines. Verify the model year, cylinder type, piston size, and compression specification before installation.

Manufacturer and vendor part number: NX-10026-BK. Brand: Namura. Fitment includes 1986, 1987, 1988, 1989, 1990, and 1991 Honda CR250R models.

Features:

• Complete Top End Kit: Includes piston, rings, wrist pin, wrist pin clips, top-end bearing, and gasket kit.
• MOS2-Coated Skirts: Rolled-on Teflon and molybdenum coating helps reduce friction, improve heat transfer, and minimize cold-seizure risk.
• Machined Smooth Head: Reflects combustion heat and helps reduce carbon buildup on the piston crown.
• Anodized Dome: Improves heat resistance and durability for demanding engine applications.
• Hypereutectic Construction: Higher silicon content supports reduced expansion, increased wear resistance, and improved high-temperature performance.
• Fitment: Designed for 1986-1991 Honda CR250R models with a Nikasil cylinder.
• Piston Specification: 66.35 mm piston size with an 8.5:1 compression configuration.