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 09-831-03 Piston Kit 09-8064-4 Screw 10-76156 / 76156 Piston 689-11631-00 / 689-11635-00 / 689-11636-00