4mm holes on a mmm
 

I am strongly considering retapping the holes on my MMM to 4mm my only concern is how will this affect my warranty?

it will void it.

you generally only use 2 of the holes to mount it, use the other 2 if you strip out the previous 2. If you go 4mm any shred of aluminum that could fall in there or anything would mess that motor up, so as Ben said, voided. (I do not speak for castle)

If it is the castle 2200 or 2650 motor you can remove the front endbell and retap the 3mm holes to 4mm without worrying about getting shavings in the motor or damaging the windings with the tap. I see no reason that if done correctly why it would void the warranty. But if you use too long m4 thread screws and damage the windings it will be out of warranty.

Yep. Just CAREFULLY remove the front endbell (don't lose any of the small parts!!) and retap. Should be fine.

As long as you don't damage it or lose any of the parts, it won't void the warranty.

Im pretty sure the prevuios poster does LOL