Originally Posted by
0010
Check your sensor wire is plugged in fully at both the motor and ESC. I had an issue with a HW 1s Stock Spec ESC where it would look like it was getting full speed on the bench, then once out on the track it would start to slow, then actually shut off! I ended up changing out my sensor wire and it worked perfectly after that.
We did check that at the track, but didn't change it out. I'll do that as a first step, since that sounds very much like what's going on here. If not, Plan B.
Thanks to everyone's help. I'll update as soon as I've figured out the cause!