I installed a 400dh motor with 8t pinion on my zoom/zap 400 heli. With 3s 1500-1800 lipo's it really rocks! I had to turn my throttle settings down to 85% to keep the headspeed below 2400 rpm. After a 10-12 minute run the motor is warm, but not hot.
I had a problem today. When I was reinstalling the pitch slider bearing casing I dropped a very tiny mounting screw. I could not find it so I replaced it with another one. When I started the heli up the motor ran pretty ok at first then stuttered and started to run very rough and jerky. I stopped everything immediately. I took the motor off the heli, removed the pinion, and pulled the casing off the motor. Guess where the tiny little screw was, wedged inside the motor! I thought, I guess I've ruined this motor!
The coils looked fine but the 6 little strip magnets (a 6 pole motor) had slid around and were bunched up together on the motor casing. I could not see any obvious glue marks so I just slid them around, even spacing then, lining them up with 6 casing holes. I then put a drop of ca on the ends of each magnet at the casing end.
I put the motor together and reinstalled it in the heli. I fired it up and it ran perfectly. I had a couple of flights and it seems to work good as new. I must admit I was a little surprised to see that these magnets do not seem to be glued to the casing, it probably worked out the best since they slid around and did not damage the coils or the magnets.
Anyway, I hope it is ok, I'll keep an eye on it, but so far so good! One tough little motor.