PISTON KIT 99-25 YZ250 66.40 C, PROX 01.2321.D RM250 03-12
4.1 Trustpilot 99.9% positive on eBay
Free UK delivery 2–4 business days
Spread the cost with 
18+, T&Cs apply
ProX Piston Kit with a 66.40mm bore. This kit features a low-expansion, low-friction piston alloy, identical to that used by major Japanese engine manufacturers. ProX pistons are precision machined using state-of-the-art CNC equipment. Most ProX pistons include a coating designed to assist in the wear-in process and reduce friction after wear-in, increasing performance. The piston size is 66.38mm. Part number 01.2321.D.
- SKU
- 56-W742.D.PX
- Brand
- Pro-X Racing
- Availability
- In Stock (1)
Fitments (51)
| Make | Model | Year |
|---|---|---|
| FANTIC | XX 250 | 2022 |
| FANTIC | XX 250 | 2023 |
| FANTIC | XX 250 | 2024 |
| FANTIC | XX 250 | 2025 |
| SUZUKI | RM 250 | 2003 |
| SUZUKI | RM 250 | 2004 |
| SUZUKI | RM 250 | 2005 |
| SUZUKI | RM 250 | 2006 |
| SUZUKI | RM 250 | 2007 |
| SUZUKI | RM 250 | 2008 |
| SUZUKI | RM 250 | 2009 |
| SUZUKI | RM 250 | 2010 |
| SUZUKI | RM 250 | 2011 |
| SUZUKI | RM 250 | 2012 |
| YAMAHA | YZ 250 | 1999 |
| YAMAHA | YZ 250 | 2000 |
| YAMAHA | YZ 250 | 2001 |
| YAMAHA | YZ 250 | 2002 |
| YAMAHA | YZ 250 | 2003 |
| YAMAHA | YZ 250 | 2004 |
| YAMAHA | YZ 250 | 2005 |
| YAMAHA | YZ 250 | 2006 |
| YAMAHA | YZ 250 | 2007 |
| YAMAHA | YZ 250 | 2008 |
| YAMAHA | YZ 250 | 2009 |
| YAMAHA | YZ 250 | 2010 |
| YAMAHA | YZ 250 | 2011 |
| YAMAHA | YZ 250 | 2012 |
| YAMAHA | YZ 250 | 2013 |
| YAMAHA | YZ 250 | 2014 |
| YAMAHA | YZ 250 | 2015 |
| YAMAHA | YZ 250 | 2016 |
| YAMAHA | YZ 250 | 2017 |
| YAMAHA | YZ 250 | 2018 |
| YAMAHA | YZ 250 | 2019 |
| YAMAHA | YZ 250 | 2020 |
| YAMAHA | YZ 250 | 2021 |
| YAMAHA | YZ 250 | 2022 |
| YAMAHA | YZ 250 | 2023 |
| YAMAHA | YZ 250 | 2024 |
| YAMAHA | YZ 250 | 2025 |
| YAMAHA | YZ 250X | 2016 |
| YAMAHA | YZ 250X | 2017 |
| YAMAHA | YZ 250X | 2018 |
| YAMAHA | YZ 250X | 2019 |
| YAMAHA | YZ 250X | 2020 |
| YAMAHA | YZ 250X | 2021 |
| YAMAHA | YZ 250X | 2022 |
| YAMAHA | YZ 250X | 2023 |
| YAMAHA | YZ 250X | 2024 |
| YAMAHA | YZ 250X | 2025 |
- General Product Group
- Engine
- General Product Type
- Pistons & Kits
- General Size
- 66.40mm
- Variant Id
- 257600
FULL DESCRIPTION
ProX Piston Kit 66.40mm Bore
This ProX Piston Kit is designed for optimal performance and longevity, featuring a 66.40mm bore size. The piston itself measures 66.38mm, ensuring a precise fit. Crafted using state-of-the-art CNC equipment, ProX pistons utilize the same advanced low-expansion, low-friction alloy trusted by major Japanese engine manufacturers. This kit provides a high-quality replacement for your original piston.
Key Features:
- Precision machined with advanced CNC equipment.
- Utilizes a low-expansion, low-friction piston alloy, same as used by major Japanese engine manufacturers.
- Coated for ultimate performance: Features OEM style Tin coating to aid the initial wear-in process.
- New skirt coating developed to assist wear-in and reduce friction post wear-in.
- Black coating is a proprietary mix of materials designed to increase performance.
QUESTIONS? JUST ASK
Talk to John or Phil. Real people, Monday to Friday, 10:00 to 17:00.
Check the fitment table on this page against your make, model and year. Not sure? Call or email us and we will check it for you before you order.
UK delivery is £4.99, or free on orders over £60. Orders ship within 3 working days, then delivery takes 2–4 business days. Delivery details
Yes. You have 14 days from delivery to return it, unused and in its original packaging. Contact us first and we will send you the return instructions. Returns policy
By card, PayPal, Apple Pay or Google Pay, or spread the cost with Klarna. Payment is taken securely by Stripe, and the options for your order are shown at checkout.
More answers in our FAQ.
Trade pricing available
Buying parts for your business? Apply for a 2BrosParts trade account.