Wiseco GP Series Piston Kit with Gaskets - Yamaha YZ125 / YZ125X (2005-2022) - 54.00mm Bore - 2-Stroke Race-Spec
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Wiseco GP Series Piston Kit with Gaskets - Yamaha YZ125 / YZ125X
The Wiseco GP Series represents the pinnacle of 2-stroke piston technology for the legendary Yamaha YZ125. Engineered for endurance racing and sustained high-RPM operation, this race-spec piston features advanced coatings and extra lightening operations for maximum performance - the same technology used by professional racers!
🏁 GP Series Race-Spec Features
- Electra Coating - Crown, ring groove(s), and pin bores coated for maximum wear resistance
- ArmorGlide® Skirt Coating - Protection from micro-welding, galling, and detonation
- Extra Lightening Operations - Enhanced throttle response
- Made in USA - Engineered, forged, and machined in the USA
Kit Includes
- Wiseco GP Series Piston - Premium 4032 aluminum alloy with Electra + ArmorGlide®
- Ring Set
- Wrist Pin
- Circlips
- Wrist Pin Bearing
- Top End Gasket Set
Key Features
- GP Series design for professional-level racing performance
- 4032 aluminum alloy construction - optimized for 2-stroke applications
- Dual coating system - Electra + ArmorGlide® for ultimate protection
- Designed for endurance and sustained RPM riding
- Complete top-end gasket kit included
- Wrist pin bearing included - everything for a complete rebuild
- Standard bore - direct OEM replacement
- 17 years of fitment coverage!
Important Notes
- Wiseco ring types are not interchangeable
- Wiseco pistons can be fitted only with Wiseco rings
- Cylinder sleeves must be purchased separately if needed
Piston Specifications
- Bore Size: 54.00 mm (Standard)
- Piston Diameter: 53.95 mm
- Stroke Length: 54.50 mm
- Material: 4032 Aluminum Alloy
- Skirt Coating: ArmorGlide® + Electra
- Style: GP Series
Engine Specifications
- Displacement: 125cc
- Engine Type: 2-Stroke
- Weight: 1.11 lbs
Fitment
Yamaha:
- YZ125: 2005-2021 (17 years!)
- YZ125X: 2020-2022 (enduro variant)
Standard vs Big Bore
This is the STANDARD BORE (54.00mm) GP Series kit for 125cc displacement. We also offer a 56.00mm big bore kit (SKU 0903-1160) that increases displacement to 134cc.
Why Wiseco GP Series?
The GP Series is Wiseco's ultimate 2-stroke racing piston. The YZ125 is one of the most iconic 125cc motocross bikes ever made - and this piston delivers the reliability racers need to win!
📦 Shipping Information
In-stock items ship next business day. ModQuad parts dispatch Monday through Thursday.
Made-to-order and custom powder coat items show their lead time at the top of this page, right next to the truck icon. These are built fresh for you, so timing varies by brand and current backlog.
Need something by a specific date? Call us at 541-668-7503 before ordering and we will check stock and ETA on that exact part. We can often point you to an in-stock alternative from another distributor.
Questions? Contact us, we respond within 24 hours.
