please HELP!!!
 

ok i have a question for everyone i need some help figuring out this problem i have with my radio/esc/servo. I have a ko helios, with a hi-tec 6965 servo, and a quantum competion 2 esc. everything works fine with this combenation. I have another car i am going to use this JR900s servo in. when i plug it all in and turn it on it looks as if everthing is ok, but when i have the throttle at any position, and turn the wheels, the motor pulses and loses power. i have no idea what is going on. if anyone could help or give me any ideas of what to do that would be great because i am at a loss. Both servos are digital servos.
thanks

try swapping servos

i have tried 3 different servos, 2 of them it does it with and one it doesnt and i dont know why.

your speed is probably went bad I would swap it out next. I had a speedo do pretty much the same thing. It is either that or the receiver at this point. You are just going to have to swap things out until you find out where the gremlin is.

i have tried it with 2 speedo's does the same thing. does it with a crystal reciever and with a spektrum reciever.

brush hanging up in the motor

also does the helios havean anolog/digital switch behind the module like a z1?