I had a similar engine long ago on a 1249 ATCO, and it was something of a pain in various ways, since it had no keyway between crankshaft and flywheel, so timing was pretty tedious. I normally was able to remove the flywheel just by unscrewing the nut until its flange applied pressure to the flywheel, then tapping the outside of the flywheel with a rubber hammer. However I think with hindsight it would have come off more easily if I'd also used a 3" gear puller, with its center-bolt against the end of the crankshaft inside the nut, and its 3 jaws hooked on the flywheel's central flange. Of course you wouldn't pull really hard with the puller - it is just an aid to the flange of the nut, and the rubber hammer around the outside of the flywheel.
