Wiseco Crankshaft Kit WPC134 — Yamaha YZ250 YZ250X 2003-2025

Product Description

Restore your engine to factory-fresh reliability with the Wiseco Crankshaft Kit WPC134. This comprehensive bottom-end solution takes the guesswork out of engine building by providing a factory-assembled, precision-trued crankshaft that meets or exceeds OEM specifications. Each kit includes the crankshaft assembly, high-quality main bearings, and a complete bottom-end gasket set, ensuring you have everything you need for a professional-grade rebuild.

Wiseco’s engineering expertise shines through in the double-forged connecting rod, which offers superior dimensional consistency and improved grain flow. The rod is shot-peened to eliminate residual stress and features precision-engineered oiling slots to maximize bearing life. With double-drilled small ends to provide extra lubrication to the piston pin, this crankshaft is designed to run cooler, last longer, and handle the high-performance demands of both motocross and off-road riding.

Top Features: Wiseco Crankshaft Kit

• Factory-assembled and precision-trued crankshaft ready for installation.
• Double-forged connecting rod provides superior strength and grain flow consistency.
• Precision-honed bearing surfaces and shot-peened rod for stress relief.
• Double-drilled small ends optimize lubrication and cooling for the piston pin.
• Complete kit includes crankshaft assembly, main bearings, and bottom-end gaskets.

Please review the detailed compatibility data below to ensure an exact fitment match for your motorcycle before finalizing your purchase.

Fitment List

Frequently Asked Questions

Q: Is this kit balanced for high-RPM racing?
A: Yes, Wiseco crankshafts are factory trued and balanced to OEM specifications, which is sufficient for almost all racing applications. If you are building a custom high-compression big-bore engine, professional balancing may be an optional consideration.

Q: Does the gasket kit include top-end gaskets?
A: No, this is a bottom-end kit. You will need to purchase a separate top-end gasket or rebuild kit to complete the top half of your engine.

Expert Pro-Tip: When installing a new crankshaft, cleanliness is paramount. Ensure your engine cases are completely free of old gasket material and debris. Always use a proper crankshaft installation tool to pull the crank into the cases; never hammer the crankshaft into place, as even a slight misalignment can drastically shorten the life of your new bearings.

Recommended Pairings:
o Yamaha YZ250 / YZ250X Performance Parts
o Assembly Lube & Premium Chemicals
o Essential Engine Rebuild Tools

At Moto-House MX, we carry the best brands in motocross and off-road performance. Our team has over 40 years of experience helping riders get more out of their bikes. Every order ships fast from our Central Florida location.

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