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 09-807 Piston Kit 09-817 / 82M-11631-02 Sealing Ring 181620 Full Gasket Kit 09-711280