Originally Posted by dlymn
monkey wrench or vice grips on shaft and resting on a board for weight distribution. Longish piece of pipe on the spanner on the wrench. penetrating oil
on thread. Should work. Check that the washer under the nut hasn't been bent up to lock the nut.
NOOOOO!!!! Why damage the shaft
Originally Posted by Wanderlust
Try an alternate solution.
Put the prop back on and place a block of wood between a prop blade and the hull
. Then go back inside and try the nut.
This works fine and best with 2 people.
Originally Posted by Jim Cate
If you have the starter off, it is often possible to jam a screwdriver into the ring gear
on the flywheel to lock up the crank.
Good possibility in snapping off a tooth and then you're screwed.
To the OP...You're on the right track with an impact driver. Use a 1/2" drive, gun type and as much air pressure as possible. Because of the snap effect of the impact, you should easily be able to shoulder the prop and impact the nut off. Make sure the rotation is correct before doing this and again, 2 people.