RE: Crawlers power cuts out.
or if you wanna upgrade your ESC at the same time, get a RC4WD Outcry esc. It can handle upto 4s lipo, is for brushed motors, has a fan and has turbo BEC. It has 2 wires for the reciever...one for signal and one for power. The rx gets full power all the time, no matter how hard you are pushing the motors.
I have the duel motor outcry esc (there is a version for singal motor) and I have it on a 1/6 scale crawler running 2 60t motors and a 200+oz steering servo. servo gets full power even if the truck is on a steep hill will the motors running hard.
it sounds lik your servos are drawing so much power that the rx is not able to work...thus intermitantly cutting your radio signal.