PROX - 01.2412.B - Piston Kit for 4-Stroke - 2012-2013 Yamaha YZ250F (76.96 mm)

ProX Piston Kit Yamaha YZ250F (2012-2013) 76.96mm Standard Bore 01.2412.B

The ProX 01.2412.B Piston Kit offers a professional-grade, economical alternative to expensive OEM parts for your Yamaha YZ250F. Manufactured in Japan by reputable Original Equipment Manufacturers, these pistons are precision-machined on state-of-the-art CNC equipment to meet ProX's exact high-quality standards. If you are looking to buy ProX Piston Kits to restore factory performance and reliability, this standard-bore kit is the industry-leading choice for your 2012-2013 machine.

This kit features a 13.5:1 compression ratio and is crafted from a low-expansion, low-friction alloy designed to withstand the high-torque demands of 4-stroke racing. It serves as the ultimate YZ250F replacement piston, coming complete with the piston, rings, wrist pin, and circlips for a comprehensive top-end refresh. The 01.2412.B Piston service kit uses an OEM-style tin-based coating to assist with the initial wear-in process, ensuring your engine runs smoothly from the first start.

Top Features ProX Piston Kit

• Standard Bore Size: 76.96mm (B-Size) for precise cylinder wall clearance
• Compression Ratio: 13.5:1 for optimized 4-stroke power delivery
• Advanced Materials: Made with low-expansion, low-friction alloy for increased durability
• Precision Machining: CNC-machined to extremely close tolerances for a factory fit
• Tin-Based Coating: OEM-style coating aids the wear-in process and reduces scuffing
• Complete Package: Includes high-quality piston, rings, wrist pin, and circlips

Fitment List

• 2012 Yamaha YZ250F
• 2013 Yamaha YZ250F

FAQ

Q: What is the difference between a "Size A" and "Size B" ProX piston?
Size B (76.96mm) is 0.01mm larger than Size A. It is typically used once the cylinder has some minor wear to maintain the correct piston-to-cylinder wall clearance according to manufacturer specs.

Q: Does this ProX kit include the top-end gaskets?
No, this kit includes the piston, rings, pin, and clips only. We recommend purchasing a separate top-end gasket kit to ensure a complete and leak-free installation.

Q: Is this a forged or cast piston?
The ProX 01.2412.B is a high-quality forged piston, designed to offer superior strength and heat resistance compared to standard cast alternatives.

Restore your machine's compression and power with the same technology used by major Japanese manufacturers. Ready to ship and race-proven.

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Yamaha YZ250F, YZ250FX Performance Parts and Accessories