mustang9955

I have a Thunder Tiger EB4 G3 buggy, one day when I turned it on and tried to use it the motor started making a clunking noise and started smoking and it would run anymore. I am using stock ESC, and a 5000mah 40c 4cell lipo but i have changed the pinion gear from a 13 tooth to a 17 tooth using the stock spur gear. Could this gear ratio have caused my motor to overheat and fry??? If so what can i do to fix this??