Hi Mark. It actually has more to do with how the motors are wound. The Iskra is i believe a continuous wound units that is designed for a static machine operation and continuous load and when adapted onto a 12v winch it was found that they simply dont load up like a series wound motor. They take the load and keep going. Lets face it that is when things really get ugly. Loaded and lacking current and the Iskra will just keep pulling.
These first came to light when a bloke had a Pallet of them sitting in a shed and figured they were the same spline count as a warn and offered them for peanuts to guys in the comp scene as spares. they were $150 and being handed out left right and centre just for the spares box. Seriously!! Excess Stock on Clearance. Give it a gfo! I was short of cash or i would have grabbed a couple. Well it turns out they are a Beast and plenty of guys running them as their motor of choice now in comps winch challenge trucks. I have not read of a single Dead Iskra motor.