Wiseco GP Series Piston Kit with Gaskets - Yamaha YZ125 / YZ125X (2005-2022) - 54.00mm Bore - 2-Stroke Race-Spec

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!