CLUTCH REMOVAL TOOL: This is a general piston stop that requires holding the crankshaft in place. APPLICATION: Can be used for clutch service or flywheel nut removal or Repair brush feeders and leaf blowers. EASY TO REMOVE: Simply remove the spark plug, screw the tool and tighten lightly. Remove the spark plug, screw the tool into position and push lightly. HIGH EFFICIENCY: The end is machined with a full radius to avoid damaging the top of the piston. Very easy to use and very handy when running your own saw or any other 2-stroke job. EASY TO OPERATE: Turn the motor clockwise or counterclockwise until you feel the impression have the piston conflict with the tool and be ready for repair. Note that most chainsaws have left-hand threads on the clutch side.