Dwayne , I did some reading a bit and dug up this thread,
http://www.rcuniverse.com/forum/rc-r...-fm-print.html In it I came across this post "
There is an additional problem with the 92185 PCM RX. The voltage where the rx shuts down is 4.7 volts rather than 4.1 volts (as all the other rxs made by airtronics) For this reason, 92185 rxs need to be run on 5 cell packs if they are in a plane with high current loads from servos. Airtronics does not easily give this information but I was able to get it out of them after a couple of bench observations under high current loads a couple of years back. " see what voltage you have at your RX . The MFU may be drawing too much (IDK) that might be a starting point .