Namura Technologies NA-40025-2R Piston Ring Kit

The Namura Technologies NA-40025-2R is a .020" over-bore piston ring set designed as a direct replacement for powersports engines requiring a 103.48mm bore diameter. Engineered to meet or exceed OEM specifications, these rings are built with the same precision materials and tolerances found in Namura's full piston kits — making them an ideal choice for engine rebuilds, top-end refreshes, or pairing with a new Namura piston.

Key Features:

• OEM-Quality Construction: Rings are manufactured to OEM specifications and tolerances, ensuring a proper fit and reliable seal without modification.
• High-Durability Ring Materials: Compression rings are composed of either highly ductile cast iron or stainless steel alloy, both of which deliver excellent wear resistance and a gas-tight seal.
• Chrome, Phosphate & Nitride Coatings Available: Coating types are matched to the specific application, cylinder sleeve type, and engine stroke (2 or 4-stroke) to ensure optimum performance and longevity.
• Application-Specific Design: Ring composition is selected based on cylinder sleeve type, sleeve coating, engine displacement, and stroke — ensuring the right material for the operating environment.
• .020" Over Bore: Designed specifically for cylinders bored .020" over standard, providing the correct ring-to-wall fit for proper compression and oil control.
• Limited Lifetime Warranty: Covered by Namura's limited lifetime warranty against defects in materials and workmanship from the date of purchase.

Namura Technologies has been producing precision pistons, rings, and engine components for ATV, motocross, and powersports applications since 2001. The NA-40025-2R ring set is designed for use with the corresponding Namura piston (NA-40025 series) and may also be compatible with OEM pistons of the same bore size — verify fitment before installation.