Wiseco GP Series Piston Kit with Gaskets - Yamaha YZ250 / YZ250X (2002-2025) - 66.40mm Bore - 2-Stroke

Wiseco GP Series Piston Kit with Gaskets - Yamaha YZ250 / YZ250X

The Wiseco GP Series represents the pinnacle of 2-stroke piston technology for the legendary Yamaha YZ250. Engineered for endurance racing and sustained high-RPM operation, this race-spec piston features advanced coatings and a single ring design for maximum performance.

🏁 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
• Single Ring Design - Reduced friction and weight for maximum performance
• 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® coating
• Ring (1x) - Single ring design for reduced friction
• 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
• Single ring design for reduced friction and weight
• 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

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: 66.40 mm (Standard)
• Piston Diameter: 66.36 mm
• Stroke Length: 72.00 mm
• Material: 4032 Aluminum Alloy
• Skirt Coating: ArmorGlide® + Electra
• Ring Design: Single Ring
• Style: GP Series

Engine Specifications

• Displacement: 249.3cc
• Engine Type: 2-Stroke
• Weight: 1.45 lbs

Fitment

Yamaha:

• YZ250: 2002-2025 (23 years!)
• YZ250X: 2016-2025 (enduro variant)

Why Wiseco GP Series?

The GP Series is Wiseco's ultimate 2-stroke racing piston. The YZ250 is one of the most iconic 2-strokes ever made, and this piston is designed to maximize its legendary performance. Whether you're racing motocross, supercross, or enduro, the GP Series delivers the reliability and performance you need to win!