A local brought his Bayou 400 in because the starter would turn over just fine, but the engine wouldn't turn over. Once the piston came up to compression, there came from the engine the typical sick cow moo sound.

Removing the alternator cover (left cover), and holding the torque limiter into the engine with a sharp punch, centered on the axle left outer end, I asked him to press the starter.

The starter motor geared output end turned, the torque limiter gear turned, and, once compression was reached at the crankshaft, the torque limiter began to no longer transmit torque onto the starter gear behind the alternator rotor.

Removing the rotor, I checked the sprag, and found it to be holding correctly (one way 'bearing' unit.)

Replacing the torque limiter resolved the problem.

However, I was curious as to how this torque limiter assembly was supposed to work, and what the failure modes are, of the part.

I applied a light press to the assembly, and found the input gear wouldn't dislodge from the axle.

Using a Dremel disc, I diced the driven gear into two pieces.

Here's how the part is constructed:

Inner side of torque limiter assembly: