PROX - 01.2224.B - Piston Kit - 53.95 mm - Yamaha YZ125
When it is time for a top-end rebuild, the piston you choose sets the ceiling on everything that comes after, and the PROX 01.2224.B at 53.95 mm delivers the precision that serious riders and race mechanics expect. Manufactured in Japan and designed to be OEM replacement, ensuring dimensional accuracy from the first start-up. Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, which means it holds tight tolerances longer and runs cooler than standard alloy alternatives. Kit includes piston, ring kit, wrist pin, and circlips, and bore - Oversize: Standard helps the new piston seat properly during break-in. Displacement: 125 cc. Whether refreshing a worn top-end or building a motor from scratch, the 01.2224.B gives you a solid foundation for a long-lasting engine. Sold as a complete kit.
Features
- Manufactured in Japan and designed to be OEM replacement
- Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances
- Kit includes piston, ring kit, wrist pin, and circlips
OEM Part Numbers: 5NY-11631-01-A0
Specs
- Bore - Oversize: Standard
- Displacement: 125 cc
- Engine Type: 2-Stroke
- Compression Ratio: Standard
- Riding Style: Off-Road
- Piston Size: 53.95 mm
- Piston Material: Aluminum Alloy
- Skirt Coating: Moly Coated
- Type: Standard Size B
- Bore Size: 54.00 mm
- Product Name: Piston Kit
- Units: Kit
OEM Part Numbers
- 5NY-11631-01-A0
Frequently Asked Questions - PROX - 01.2224.B - Piston Kit - 53.95 mm - Yamaha YZ125
How do I know if this part fits my vehicle?
Check the fitment information listed on this page against your exact year, make, model, and (where applicable) trim, engine size, or configuration. If your exact vehicle isn't listed, or you're not sure, use the product chat on this page or contact our support team before ordering - we're glad to help confirm fitment.
What does it mean if a product is listed as universal fit?
Universal fit means the product is designed to work across a range of vehicles, not that it's guaranteed to fit every one. Compare the listed measurements, mounting requirements, and connector or hardware specs against your specific vehicle before ordering, since some installations may need additional hardware or minor fabrication.
Where can I find installation instructions for this product?
General installation notes are provided above where available. For detailed step-by-step instructions, refer to the manufacturer's documentation included with the product, or use the product chat on this page for questions about difficulty, required tools, or whether professional installation is recommended.
What if I have more questions about this product?
Use the product chat on this page for fitment, specs, installation, and compatibility questions, or contact our support team directly for help before you order.
