Most likely this:
"OR will it start to run and fry out my arduino because its sucking too much power form the board?"
IO pins can supply 40mA, but there is no built in limiting. DC motor looks lik a short to Gnd to an IO pin
Connect +9 to Motor'+', Motor'-' to NPN transistor collector, with emitter to Gnd.
Connect arduinon IO pin to 180 ohm resistor to transistor gate. High out will turn on transistor and let current flow thru motor.
Use a PWM pin if you want to add speed control.