Glitch - str servo turns to right when throttle at full speed?

[sweli]

Thx in advance for any help.

OK, it is not one of my scalers doing it, it is the RC18 my kids bash on.
Steering works correctly, when truck not moving.
Throttle works correctly.

When driving a straight line, as soon as the throttle goes above 75%, the truck turns right? It does it if you are holding it in the air also. The servo turns to its EPA.
Steering is slightly twitchy when at 1/2 throttle.

It is bone stock, which has the stock XPS ESC, servo, motor, and 6cell.

I am wondering if the BEC current or voltage is dropping out when at full throttle?
Or if the current from the Batt was dropping at full throttle.
I have tried different batts, but not ESCs or RXs.

Thoughts?

[jamesdicken]

Stock radio?

[sweli]

Stock Tx and Rx.
Did try a different Tx right away.

To change Rx would take a bit to get it out of another rig.