Issues sxx?

[RobPaynter]

Just fitted a brand new sxx version 2 into my new dex210 and a new x12 6.5t. Set the speedo as per instructions ran fine on the bench. But as soon as I put it on the floor it would not go more than 3 foot before turning itself off. Changed motor and receiver still no better. Turned the high point on the transmitter down and it was better but only managed 4 laps before it turned off and now won't turn on at all. Just woundering if anyone had the same problem or any info that might help me understand this.