I’ve been hunting a proper flywheel puller for this for the past hour with no luck… It’s a tiny, little, sweet baby Jesus .18… on top of that-it’s a tiny, little, sweet baby Jesus marine flywheel… annnnnnnnd, it’s aluminum over steel with a brass collet… So heat, and/or cold isn’t gonna be a ton of help.
I don’t wanna be the bearer of less than awesome news here, but I’d be willing to bet, it’s gonna involve some caveman shiit…
What really sucks is that you don’t wanna scar up your spotless aluminum flywheel, and that’s gonna require some serious thought, and then even more seriouser patience, and steady AF hands… while a crankshaft SHOULD be plenty “hard”, I’d for sure be afraid of damaging the threads even with decent engagement of a nut… If you go this route, I would advise against grabbing the flywheel. I would sit the crankcase on a block of wood with the crankshaft perpendicular to said block, and place something reasonably hard directly on the end of the crank, and give it a medium whack. OBVIOUSLY not something metal (or harder than the crank), so that you don’t fold that last thread.. Obviously this is after removing the set screw from the flywheel if there is one (I see the flat in the crank snout in the diagram, so it’s possible).
The only thing I’d be worried about is splitting the cast aluminum crankcase, but with a medium whack, and the case perpendicular to the block of wood, this will be the safest procedure without access to a proper puller IMO.
FWIW-there seem to be an assortment of different setups; some involve a “keyed” flange as you made mention of, and some use a collet.. Some look like BOTH.. either way-once the flywheel nut is out of the picture (as shown in your photo), and any set screw in the flywheel has been removed, it’s simply being retained from the flat, or flat(s) on the crank snout, the grip of the collet, or both. There’s no amount of heat, cold, or penetrating lubricant that’s gonna do anything at all-it needs mechanical “persuasion”.
