This complete kit includes a new precision-made, stroked crankshaft and nickel-carbide plated cylinder with enlarged water passages and revised porting designed specifically for this kit. The cylinder head is also newly designed with increased water passages. Kit has everything needed for a complete installation except required crankcase machining. Includes crankshaft, connecting rod, cylinder, cylinder head, precision-made piston with rings, clips, wrist pin, studs, nuts, O-rings, and gaskets (different thickness base gaskets to adjust squish).

YZ models are for closed-course use regardless of modification.