PROX Piston Kit for Yamaha YFZ450 (2004-2009) and YFZ450R (2009-2011) — 12.0:1 Compression

Engineered for reliable OEM-grade replacement, the PROX Piston Kit delivers consistent power and durability for Yamaha YFZ450 and YFZ450R engines. Manufactured in Japan by trusted Original Equipment Manufacturers to PROX specifications, this kit is built to exacting standards for strong heat resistance and long service life.

The kit is designed as a complete top-end rebuild solution, including pistons, piston rings, wrist pin, and circlips, so you can refresh the engine with all necessary components in one package. It supports both sleeved and plated cylinder configurations, with a broad range of oversizes available to match worn bores and restore original performance.

Key specifications and fitment:

• Compression ratio: 12.0:1, aimed at increasing power while preserving reliability.
• Applications: Yamaha YFZ450 (model years 2004–2009) and YFZ450R (2009–2011).
• Material quality and engineering: PROX leads with cast and forged piston designs crafted to replace OEM parts with precision and consistency.
• Kit contents: Pistons, piston rings, wrist pin, and circlips included for a complete installation.
• Availability: Sleeved cylinder piston kits in standard size and a wide range of oversizes; plated cylinder piston kits in standard size and oversizes (A, B, C, D where available).

Whether you’re restoring an aging ATV, pursuing maintenance efficiency, or chasing a measured performance upgrade, this PROX piston kit offers a durable, precisely engineered option tailored to your Yamaha four-stroke’s needs. Part number 01.2435.C.

Excellent economic alternative when you are looking for an OEM quality replacement piston

Mainly manufactured in Japan by reputable Original Equipment Manufacturers to ProX exact specifications and high quality standards

Sleeved cylinder piston kits are available in standard size and a Wide range of oversizes

Plated cylinder piston kits come in standard size, as well as in A, B, C and D oversizes if available

ProX leads the industry in cast and forged pistons made specifically to replace OEM parts

Comes complete with pistons, piston rings, wrist pin and circlips

The PROX Piston Kit for Yamaha YFZ450 models from 2004 to 2009 and YFZ450R models from 2009 to 2011 offers reliable performance and durability. Designed with precision to meet the demands of high-performance off-road riding, this kit provides a significant upgrade over stock components. Crafted from high-quality materials, the piston ensures consistent power delivery and improved engine efficiency. The kit includes all necessary components for a comprehensive rebuild, making it an ideal choice for enthusiasts and professional mechanics alike.
Constructed with a 12.0:1 compression ratio, this piston kit enhances engine power while maintaining reliability. The kit's design emphasizes heat resistance and longevity, ensuring optimal performance under demanding conditions. Easy to install, it offers a perfect fit for Yamaha YFZ450 and YFZ450R models, restoring engine performance to near-new condition. Whether for restoration, maintenance, or performance upgrades, this piston kit is engineered for durability and precision, helping you get the most out of your ATV.
Trust PROX’s reputation for quality aftermarket parts and experience the benefits of a well-engineered piston kit designed specifically for your Yamaha ATV. This kit is your solution for restoring or enhancing your vehicle's engine performance, ensuring smooth operation and reliable power for all your off-road adventures.

Features:

• Designed for Yamaha YFZ450 (2004-2009) and YFZ450R (2009-2011) models

• 12.0:1 compression ratio for increased power

• High-quality materials for durability and heat resistance

• Complete piston kit includes all necessary components for installation

• Engineered for reliable performance and longevity