If you have a large pipe wrench, use that to hold the adapter. No pipe wrench remove the spark plug, set the piston at BDC, stuff cotton rope into the cylinder and turn the adapter until it stops. Make sure you leave some rope outside the engine so you have something to grab when you complete the job.
Actually it doesn’t work that way. You can’t take a mower blade off without holding or wedging the blade to keep from spinning but with an impact, one doesn’t have to even hold the blade, for example
#9
Fish
Folks often think that an air wrench or drill is an impact, when it is not.
Here is a video I made to show folks how to remove a flywheel.
