PACKARD PERFORMANCE PERFORMANCE CAMS FOR YAMAHA YXZFree shipping in the lower 48 states. PACKARD PERFORMANCE PERFORMANCE CAMS FOR YAMAHA YXZ Why performance camshafts? _ The camshaft uses lobes (called cams) that push against the valves to open them as the camshaft rotates; springs on the valves return them to their closed position. A larger lobe equals more air and fuel. More air and fuel equal a bigger BOOM in the combustion chamber which in turn equals more horsepower. Cam swaps are critical and