More mini starter insanity

[midascircle]

my mini starter just puked out again. Fourth starter in less than 1500 miles. All fail the same way. Makes a little noise and then stays engaged, sort of. The main drive sticks on as in spinning the gear however solenoid is not engaged. Will stay spinning until battery is unhooked. Double and triple checked shimming and clearances. Wrapped and insulated starter and all related wiring. So far two starters straight from the general, one off the shelf local, and one built by a local starter repair shop. All the same. Don't consider my self a dummy by any means(30 year exp. journeyman mechanic) but this thing is making me feel like a raw rookie. Any fresh ideas would be welcomed and appreciated.
HELP!!!!

 

[Speedjohnston]

How is it wired including wire sizes?

 

[midascircle]

12ga feed power to solenoid(uses a spade connection for hookup). Standard battery cable for main power. Unfortunately can't tell ya the cable gauge as car is in the garage and I am not. Getting all sorts of power though(apparently too much as the damn thing won't turn off).
Solenoid is simply a single wire from crank signal from ignition switch.

 

[Camaro75LT]

Slightly warped flywheel could be damaging the starters.

 

[midascircle]

Could. Have never seen that do anything other than beat up a bendix before
But first time for everything. Still see something new every day in this business

 

[hhott71]

I used a phord solenoid and the jumper from the "S" to battery cable on the starter and had the same issue of the starter staying engaged a couple of seconds after starting.
I went back to normal GM type wiring and solved that issue.

 

[midascircle]

Original wiring(albeit slightly larger). I'm 99% sure it's a solenoid issue. internal plate is sticking. Problem is how to solve it once and for all.

 

[Mountaineer]

Is it possible to go back to a stock size starter? Are the GM starters the S10 mini type?

 

[Speedjohnston]

Are these all the same brand?

 

[midascircle]

Two were direct from gm performance. One was Napa. One was built by a local starter specialty joint
Only reason I went with the mini starters is I was under the impression they would handle the heat better. May try an o.e.m one yet. Couldn't be any worse