Restore proper engine sealing with Namura NA-40000RN piston rings, designed for use with 63.94 mm Namura pistons in compatible Yamaha applications. These replacement rings are engineered to support reliable compression, help control oil consumption, and maintain efficient combustion when installed with the correct Namura piston assembly.
Namura manufactures these rings for Namura pistons only, making correct piston and ring compatibility essential before installation. The 63.94 mm size is suitable for engines specified for this piston-ring diameter, while the Yamaha fitment reference helps identify compatible applications. Always verify the engine model, piston specifications, ring configuration, and service-manual requirements before ordering or installation.
Built as a replacement component for engine maintenance or piston service, the Namura NA-40000RN ring set helps return the cylinder assembly to proper operating condition when existing rings are worn, damaged, or no longer provide adequate sealing. Installation should be completed by a qualified technician using appropriate ring-gapping, orientation, lubrication, and break-in procedures. The manufacturer part number is NA-40000RN, and the vendor part number is 186-4000RN.
Features:
- Size: 63.94 mm piston ring size
- Fitment: Designed for compatible Yamaha applications
- Compatibility: For Namura pistons only
- Brand: Namura
- Manufacturer Part Number: NA-40000RN
- Vendor Part Number: 186-4000RN
- Function: Supports compression sealing and oil control in the engine cylinder