ORIGINAL: dpw
This is just a little FYI. I have a Mintor 22 that I bought a year ago and flew on a RedwingRC profile. By the end of the summer the engine started having some issues. It would run part of a flight and then just quit, eventually it wouldn't start and continue to run. In the fall, I sent the engine to Top Dawg for a checkup and service and they returned it saying that it started & ran great. I mounted the engine and found it still wouldn't run for me. It would fire (pop) but not continue to run.
A 10 hour drive to Toledo and back gave me a chance to think about why the engine would run for TopDawg but not for me and the answer had to be the ignition battery. When I got home, I replaced the 4 cell NiCd pack measuring 5.1 volts with a 5 cell pack and the engine immediately became friendly again

The Mintor 22 starts, runs and transitions good, and I'm now a happy customer again.
Since the ignition unit says 4.8 to 8.4 volts, I just had not considered the possibility that 5.1 volts was not enough to make it run.
That is good to know. So far my battery pack seems to work very good. The power in the pack seems too last a very long time. Capt,n