I run an Associated SCT on indoor carpet. I've changed to gearing of 25/75 for added top-end, per recommendations of others. But I find my motor is overheating. I'm using a brushless Tekin 17.5. The carpet is very high traction, too.

I think I need a lower ratio and have considered using a slightly smaller pinion, but the gears won't mesh because the screw holes/slots on the motor bracket limit the amount of movement for making a good mesh.

Is it common to file the slots to allow for better mesh? Do I run the risk of weakening the bracket? I would think filing the least amount as possible is best, if that's an option. Is there a better method?

Thanks for any solid suggestions.
Beas

First I would try going to a different spur (a bigger one) you can accomplish the same thing you're tring to do without trying to driiling