9l mounting hole
 

How long of a screw or thread could you screw into a fiegao 9l mounting screw hole?

That depends on the motor mount. The Feigao has about 3mm of available thread on the front endbell. Just make sure the screw doesn't thread beyond the endbell and you will be fine.

Good point!

I just saw on my new Lehner ther's only like 2mm's available :C:
how is this holding up?? Easy to strip, I guess.

The Feigao threads look much better. Deeper.

There is plenty of thread on the Lehner motors to hold them. You just have to make sure not to thread a screw past them.

Sure! I measured it and it looks as if 2mm should be save.
Yeah, I like to do this properly, measured the mount and already got some suitable screws ready.

The lehner's have 3mm of thread. I use the stock mounting screws with a big (approx 4mm.) nylon washer on it.