I have one of those 2x55o ofna starter boxes and i used to use two 7.2V stick packs for it but it's just sooo weak.
My brother has one with the single 750 motor and it's VERY good choice for any engine.

What i want to know though is whether i can use instead of two 7.2V packs...two 8.4v packs and increase voltage on the 2x550 starter box.
Won't this increase the torque?
The time that these motor will have to work on that high voltage isn't much to thing that they might get toasted right?