Namura Piston Kit 66.35mm Dual Ring – Yamaha YZ250 '99–'24

Namura provides high-quality piston options to suit a wide range of applications, including direct OEM replacements, high-compression variants, and multiple oversizes. B (0.01 mm) and C (0.02 mm) oversizes are also available, helping to extend the service life of expensive plated cylinders. Select applications are supported with big-bore piston kits. With the addition of MOS2 coating and hard anodising, Namura delivers improved performance and durability, without the premium price.

Features:

• MOS2 (Teflon/Molybdenum) Coated Skirts: Applied using a rolled-on process for a bond up to 10 times stronger than typical spray coatings. Improves heat transfer, reduces friction, and helps prevent cold seizures.
• Machined Smooth Heads: Reflect combustion heat and minimise carbon build-up, protecting the piston crown. Testing indicates potential gains of up to 6% in horsepower and fuel efficiency.
• Anodised Domes: Enhance heat resistance and durability, with up to 75% greater strength compared to non-anodised pistons.
• Hypereutectic Casting Process: Increases silicon content to reduce expansion, improve wear resistance, and withstand higher cylinder temperatures.
• 0.50 mm oversize up to 100.47 mm, with a 9.2:1 standard compression ratio.
• Includes piston (individually wrapped), OEM-quality rings (boxed separately), wrist pin, and circlips.