Hello,I have a hobbyking xerun 120 a sensored system in my truck. I'm using a 2 s 5000 mah lipp battery and 8.5 turn brushless motor.When I put it under full load the steering servo moves by itself for a split second. What's up? Thanks, paolo.

What servo? You're on the right track it seems, BEC is not supplying enough voltage/amps to operate your servo properly. You can get a $5 capacitor and plug that into the aux.port in the receiver or solder in a Castle external BEC but the 1st suggestion should work for ya.

Also what receiver are you running ? The XeRun 120A should have a 3A BEC, that should be ample to run a power hungry servo however if your receiver will brownout at a higher voltage you will see these issues.

A capacitor on the 6v BEC line will certainly help.

I have the same esc. I have to keep a power cap plugged in or the servo goes crazy.

Hw/hk upped the bec power on the v3.1 I believe.

Where can I get a power cap? Thanks Paolo.

Just do a search for glitch buster or power capacitor from whatever hobby shop/ online store you use.

Make sure to get one with the pigtail that plugs into a receiver.

Just get this one...does the job.

http://www.amain.com/rc-cars/spektru...-spm1600/p6570

Thanks , paolo.