40S starter spinning w/o crank: removing starter?

I've been using an old 40S with bushhogging, hauling, and disking. The last few times, though, we've had to push-
start it. Suddenly, a day after working fine, on ignition the starter whirred and spun but there was no audible connection with the engine, no cranking at all. I suspect something wrong with "power train" between starter and cylinders? I tried to remove the starter, but am faced with an unusal bolt: an "allen key" head turning inside a larger, standard hexagonal bolt. Here's the immediate question: do they both turn the same way?

More generally: ideas about what could be wrong, and how to get it working again?

Thanks!
john.

On your starter problem.. You will know more when you get it out but the usual problem is a broken starter drive [bendix].. Those 40�s are also noted for taking the teeth off the flywheel but it usually grinds when that happens..

Pull the starter out then post back once you find the problem & we can help you repair it..

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