Have a ballistic Fantom 17.5 (one of several but fastest one). I have only gotten a couple battery packs through it. Runs great the first pack at the track. Comes off about 115-120 degrees. Second pack acts like the sensor wire failed. This is about 45 min- 1hr after running 1 pack for 7 minutes. This has happened twice. I've replaced the sensor wire, and even took it back to my motor tuner. He couldn't find anything wrong with it. He reshimmed, tested all the numbers, tested sensors, and even put it on a dyno with load for a few minutes. Appeared no issues with the motor, granted it was only on the dyno a Minute or so. I Soldered it in today. 1 great pack and same thing. Like the motor has a 1 pack life when soldered in. Put a few other fantoms in my buggy sensequently and no issues. My esc is a new maclan MMax. Anyone know what can cause this? Thx

Maybe the sensor board in the motor?

Would be my guess as well. When you get intermittent motor issues and everything else has been ruled out, that often winds up being it.

I found one of my esc wires routed to the receiver had been pinched under the battery thumb screw. I'm hoping that is it. But can't figure out why it causes problems with only 1 motor... sensor board is fine and tests well on the skyrc motor analyzer

I have a new fantom doing the same thing, they sent me a new sensor board, haven't got to run it yet, is yours doing ok now?

No - thought it was the esc wore. Put it in another buggy. Same thing.

My bet is still on the sensor board if you can't find anything else, even if it's checking out ok on the motor analyzer.