07 Carryall 1 surge at WOT

[blackhatmav]

I am trying to figure out a surge on this unit. It came in for not running or charging initially. We installed all new Trojan batteries, charger to cart cable and charging OBC and associated harness. The cart now charges and runs well, but also surges at full throttle. Fast then slow the fast etc..... Took a chance and installed a new MCOR to no avail. Does this cart have the three resistors that I have read about on this forum? Have looked, but have not found them. The push test for the speed sensor is working. Buzzer comes on and resistance applied. Serial number FD0721- Any suggestions are welcome.

[jjance]

From what I've read torque bumps are caused by something wrong with the field windings in the motor. I would double check all connections going to the motor. MCOR would have my first suggestion but you have already eliminated that.

[blackhatmav]

Okay, cleaned and retightened all connections. No difference. I also found that the cart will sometimes feel like regen braking when lifting off the throttle. Other times the cart will just coast. No rhyme or reason. Anybody think that the controller might be causing these speed related issues?