RE: speed 400 break in
Use distilled and preferably deionized water and not just tap water. Running at about 7-9 amps on 7 cells my 7.4v 400 motors give me about 50-75 good flights. I do run them in my glider for 4 one minute runs and they cool down so continuous runs and xtra heat will shorten life. If I notice a reduction in performance or alot of sparking at the brushes i swap them out cuz they are cheap. Also, some people break them in again in water and claim the performance improves a bit.
Be careful with the airhose deal (low pressure)...I have blown off the putty-like green stuff on the windings...the motor shook awefully bad. I guess this stuff is stuck on here and there on some motors by hand for balancing at the factory cuz I seen fingerprints in it.