Hi Mike! My friend has the same problem, and it's the starter that doesn't haven enough power to turn the motor, he bought a brand new hobbico high torque starter and it just doesn't turn it even when using a car battery; then when we switch to my hobby people's high torque starter and it just turns fine and starts right on the button even with a dry cell 12 volt battery(flight box battery) , so my advice will be try another brand or type of starter and see what happens.