D2 pony electric starter

If you're an ACMOC member you can access the technical library which has the manuals.

CrawlerAddict

There is no clutch on the starter. It is just a motor with a gear that engages another gear in the housing. The gear in the housing is directly connected to the pulley. Sounds like you need to rebuild the starter or the solenoid.

Worn belt/pulley could cause slippage, or just out of adjustment. If you are using 6 volts, those do not spin very fast; a 12 used conservatively normally spins nice and fast, just don't crank on it forever, otherwise you risk damaging the starter. If your 12 doesn't spin very fast, it likely needs servicing.
I would take the hood off and start with checking the belt tension. JM

Hi Tim, I had the same symptom on my unit and it was due to the belt slipping on the starter motor end. The arrangement is that the starter drives a bendix (or something, can't quite remember) that engages with a gear that then drives the driving pulley on the starter. That pulley then connects to the pony flywheel via the belt. There's a good chance that your belt is slipping if the bendix is engaging properly