This complete cylinder kit includes a new 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 cylinder, cylinder head, precision-made piston with rings, clips, wrist pins, studs, nuts, O-rings, and gaskets (different thickness base gaskets to adjust squish).

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