All Kohler clutch retaining bolt holes are 1/2" fine thread. Bolt length depends on application and clutch model.

HA! No it sure wasn't magic. The magic is when it spun off there it didn't kill me. All that happened is that I need a new hood.
I dunno much about this machine, it isn't an Elan or a KM914, so I'm busy paying the steep learning curve.
Thanks for the thread call. I will get it back together tomorrow.
I bought the machine because its a 1972 Panther with the back plastic around the taillights and gas tank  still intact. I have never seen a Kohler engine before, or its clutch. My biggest mistake was trusting the guy who put it together, without having done more research on the engine. Heck, even a picture of the PTO side of the engine would have shown me a bolt head sticking out.
BPJ

Well I bought a 6inch 1/2 20 bolt and cinched that clutch down, put a belt from a wankel panther on it and fixed the kill switch.
I started it and took it for a ride. Wow! It has sooo much more top end then the wankels. It sucks at a crawl. Barely would crawl over the plow berm to the snowmobile park. I opened it up on the road and it haul assets though.
I am confident that I should proceed with a new belt and find a recoil.

Should I straighten out the bent fixed clutch sheave or just buy a new one? It got bent when it went for its little fling. I keep waiting for it to explode.
BPJ

Thanks,
Well, we know that it'll come off easy.
How do identify the clutch? BPJ

That appears to be an Arctic round shaft. It had some issues right from the factory. Arctic Cat took a bath on a recall of that clutch. It was replaced by the very similar Arctic Hex clutch. While I would recommend you replace it because of the bent sheave, the parts may be of value to someone restoring a machine of that era.