Yamaha YZ250 1999 - 2026 Namura Piston & Rings Kit 66.35mm

Namura Piston & Rings Kit

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.

Fitment Details

• Yamaha YZ250 1999
• Yamaha YZ250 2000
• Yamaha YZ250 2001
• Yamaha YZ250 2002
• Yamaha YZ250 2003
• Yamaha YZ250 2004
• Yamaha YZ250 2005
• Yamaha YZ250 2006
• Yamaha YZ250 2007
• Yamaha YZ250 2008
• Yamaha YZ250 2009
• Yamaha YZ250 2010
• Yamaha YZ250 2011
• Yamaha YZ250 2012
• Yamaha YZ250 2013
• Yamaha YZ250 2014
• Yamaha YZ250 2015
• Yamaha YZ250 2016
• Yamaha YZ250 2017
• Yamaha YZ250 2018
• Yamaha YZ250 2019
• Yamaha YZ250 2020
• Yamaha YZ250 2021
• Yamaha YZ250 2022
• Yamaha YZ250 2023
• Yamaha YZ250 2024
• Yamaha YZ250 2025
• Yamaha YZ250 2026