u can change it to a dewalt drill motor. if u go brushless u need to get a sensored system or it will cog like crazy(cog is the cogging motion of a motor, not center of gravity which some ching made up, center of gravity is call cg) i had mine brushless and flipping every corner, end up using stock esc with dewalt motor. tons of power added from the stock u should give it a try.
Ching, may I know what is dewalt drill motor? And where to get it?
many thanks
Dewalt 電鑽 motor, get it from ebay or maybe some hardware store carries them i dont know i got mine from ebay search "14.4v dewalt motor" on ebay very low cost but increase speed, torque on ur summit by A LOT(and cost around 30usd), but u need to solder the wire correctly to get it work, it is very simple, just move the wires from ur old motor to the dewalt one! i ran it in water without problem as well! good luck!