Wiseco GP Series Piston Kit with Gaskets - Yamaha YZ125 / YZ125X (2005-2022) - 58.00mm Bore (+4.00mm BIG BORE) - 144cc - 2-Stroke Race-Spec
- Ships next business day
- 30-day hassle-free returns
- Call us: 541-668-7503
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The Wiseco GP Series represents the pinnacle of 2-stroke piston technology for the legendary Yamaha YZ125. This is the MAXIMUM BIG BORE kit (+4.00mm) that increases displacement from 125cc to a massive 144cc - giving your YZ125 extreme power gains with GP Series race-spec features!
✓ Fits:
- 2005-2022 Yamaha YZ125 / YZ125X
✓ 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
- Stock Bore: 54.00mm = 125cc
- +2.00mm Bore: 56.00mm = 134cc
- +4.00mm Bore: 58.00mm = 144cc (MAXIMUM!)
✓ What's Included:
- Wiseco GP Series Piston - Premium 4032 aluminum alloy with Electra + ArmorGlide®
- Ring Set
- Wrist Pin
- Circlips
- Wrist Pin Bearing
- Top End Gasket Set
Note: Crankcase clearance is required. The larger piston diameter may require crankcase modification for proper clearance.
Note: Electra Coating - Crown, ring groove(s), and pin bores coated for maximum wear resistance
Note: ArmorGlide® Skirt Coating - Protection from micro-welding, galling, and detonation
Note: Extra Lightening Operations - Enhanced throttle response
Ships fast from DuneGoonShop!
📦 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.
