Small Engines (Lawn Mowers, etc.): electric PTO clutch removal - troy-bilt garden tractor, impact gun, ohv engine

Question
it's a 2002 model BHO9.  A week or so the PTO would not engage, so I removed the deck and tried to remove the clutch but I can't seem to figure out how to lock the shaft so I can wrench it off at the bottom.  I gave up and re-engaged the clutch and it started working again.  But when I was working on it I saw that the belt is in very bad shape and needs changing.  Hopefully I'm missing something simple but I just can't figure out how to lock the PTO clutch to remove the bolt from underneath.  Thanks in advance for any help you can give....

Answer
There are a couple of ways to keep the engine from spinning to remove the PTO retaining bolt.  You cna remove the top engine cover to access the flywheel nut.  Hold the flywheel nut with a large socket and ratchet.

You can also try removing the spark plug and inserting an old starter string, with a bunch of knots tied in it, into the spark plug hole.  As you rotate the engine the piston will hit the knots in the string and prevent the engine from rotating.  If you have an OHV engine I would not use the knot method.

An air impact gun will remove the retaining bolt really easy.

I would not remove the PTO to install a new belt...I would remove or just loosen the deck.

Eric