PISTON STOP Fits 14mm sparkplug hole. 12614Helps remove clutch, flywheelKart, Motorcycle, Mini Bike, Moped, Go-Ped, Scooter, Trimmer, Chainsaw, Blower, MowerMost 2 Cycle &4 Cycle Engines & Motors with 14 mm sparkplug hole.Saves damage to Pull-Start assembliesJust thread the Piston Stop into the sparkplug hole, run the piston up against the end and the crank is locked solid.Great ToolBox Accessory!