Namura Top End Repair Kit (0.50mm Oversize – 47.95mm)

Namura Top End Repair Kit (0.50mm Oversize – 47.95mm)

Part Number: NX-40085-2K

Give your dirt bike new life with a complete Namura Technologies Top End Repair Kit. Engineered as a direct fit upgrade for 85cc Yamaha models, this kit features high-silicon hypereutectic aluminum construction and advanced skirt coatings to deliver reliable power, excellent heat dissipation, and long-lasting performance.

Key Features:

• MOS2 (Molybdenum/Teflon) Coated Skirts: A rolled-on application creates a bond up to 10 times stronger than traditional spray coatings, significantly reducing friction, aiding heat transfer, and helping prevent cold seizures.

• Anodized Piston Domes: Increase heat resistance and structural integrity—up to 75% stronger than non-anodized pistons.

• Machined Smooth Heads: Reflects combustion heat to minimize carbon buildup, protecting the piston head and maintaining peak engine efficiency.

• Hypereutectic Aluminum Alloy: High-silicon content controls thermal expansion under high operating temperatures, maintaining correct tolerances.

• Premium Riken Rings: OEM-quality ring set included for maximum compression sealing and power transfer.

What’s Included:

• (1) Namura 47.95mm Oversize Piston (+0.50mm / .020" Over)

• (1) Complete Set of OEM-Quality Riken Piston Rings

• (1) Wrist Pin & Circlips

• (1) Complete Top-End Gasket Set

Fitment:

• 2002–2018 Yamaha YZ85

⚠️ Important Fitment & Cylinder Notice:

This kit is a 0.50mm Oversize (+0.50mm / .020" Over) piston kit designed for a 47.95mm cylinder bore. Cylinder boring or honing is required for proper fitment. Always accurately measure your cylinder prior to installation to confirm correct piston-to-wall clearance.