Products Snowmobile- YamahaPiston Kit Back Piston Kit 09-816 Item number: 09-816 Bore Size: 73mm Stroke: 64 Fit on model: 1983-91 Yamaha VMX 540 You May Also Be Interested In Piston Kit 09-826-02 Piston Kit 09-829 / 8AB-11631-00 / 8CJ-11631-00 Piston Pin 62T-11633-00 Cylinder sleeve 496-44110-00