Small Engines (Lawn Mowers, etc.): Removing Drive Pulley, air impact wrench, pulley bolt

Question
I have a old john deere 111.. I need to remove the main drive pulley, but the engine needs to be seized in order to remove the bolt.. How do i get the engine to stop from moving?

Answer
Easist way to remove the bolt is with an air impact wrench.  Another option is to use a flywheel strap wrench and hold the flywheel why you remove the bolt.  Both of these options require additional tools.

The third option you can try is to use some old starter string cord.  Tie several knots on one end of the string.  Remove the spark plug and insert the knots in the spark plug hole.  Leave enough string sticking out so you can remove the knotted end.  The idea with this method is as you turn the pulley bolt the piston will rotate to the top of the cylinder.  When the piston hits the top it compresses the knots at the top of the head and the knots will not allow the piston to continue rotating.  Sometimes you have to tie a bunch of knots to keep the crankshaft from rotating.  I've used this method a lot, more on two cycle engines, but you have to be carefull as you start removing the bolt because sometimes the knots will compress and the crank will turn...won't hurt anything but you could bang up your knuckles.  

Last method is to hydro lock the engine by filling the cylinder with oil.  Principle is the same as the knot theory but you have to clean out all the oil when you are done and  the engine will usually smoke for a while as it burns out some of the oil you could not remove.  I've used this method as well but mainly on water pumps to remove the threaded impellers.

Recommend an air impact or the knot method.

Let me know if this helps.
Eric