Lynx

There are methods for determining the charactoristics of a DC motor but they're difficult to the uninitiated. You have to be able to measure the current while the motor is stalled, the voltage at the motor terminals while the motor is stalled, and be able to measure the voltage the motor generates when you spin it at a certain RPM. Also the no load current of the motor. All of those values allow you to generate (mathmatically) everything you could ever know about your motor, accept the max voltage it can take and the heat disipation ability of it because both of those depend on the environment it's in too much. There's a program called motocalc that can help you generate the numbers you need from readings you get and just about anything else you need to find out how an airplane will perform with a given motor.