For testing a brushless motor, it's best to test with a known good ESC. However if you are worried about damaging the ESC there are other ways of testing the motor. I know you trashed the stock ESC, but you do have the one from the other heli. But, read on before you hook it up just incase there is an issue with the motor.
The first thing you will need is obviously the motor and a drill of some kind. Electric drills are best becuase they can hold the same rpm unlike a battery drill.
Chuck the motor up in the drill holding the case with your hand (where the wires come out). Spin the drill up to at least 1000rpm. You should see NO buildup of heat in the motor and there should not be any resistance. If there is resistance or heat, then you have a short in the windings and the motor is trashed.
Second test you will need an AC volt meter. Label the wires #1 #2 #3. chuck up the drill and put the meter on an AC setting (you will have to find your setting after starting teh first test. Run the drill up to full speed with the meter connected to #1 & #2, then #2 & #3 and finally #3 & #1. The output voltage should be exactly the same across all 3 polls.
The third test will build some heat, so be careful. It's the "Brake" test. wire all 3 wires together and spin the motor up while holding the can. With the wires shorted out to each other, it will act like a brake. DON'T DO THIS FOR MORE THAN 10 SECONDS!!! You should feel drag in the motor and it should remain constant. If you feel a chugging, then the motor is bad.
Remember a brushless is just a 3 phase motor. I hope this helps you in testing your motor to make sure it's good. Make sure to spin it for a while on the first test with nothing connected to the wires. This is just a baseline test, and if you have damaged the windings in the can, this will create a brake effect and built some heat. Hope this helps.
