My gem shutters and jumps when starting, it has an upgraded motor, I think it is 7.5 volt. It also surges when cruising on the road at 30 mph or so.
If the programming hasn’t been modified check for stuck brushes and a damaged commutator. Ventilated motors get contaminated and brush holders get dirty which causes brushes to stick. This type of motor should have the brush assemblies serviced every 2 to 3 years.
Dragging brakes are also a possibility.
Took out the motor, it needed cleaning, completed the cleaning, still does the same thing, jumps, shudders, and has a hard time engaging when starting out, still surges at 30mph. After the initial start, it smooths out. I am looking at the half shafts or something in that area. Any ideas.
1 Does it still stutter when starting out?
2 If yes could still be a motor problem - check for open commutator segments
3 If no, could be programming problem - has any programming been done since the last time it was running properly?
4 Controller problem
5 if possible try another motor.
This exact problem has happened to me a couple of months ago after a program change. I could not get it back, I swapped motors with my other cart and the problem went away. Both carts run perfectly. (5 hp motor T1 controller)
Thanks, it still has a little jerk at start but smooths out. Having worked on it lately.
JP
I had shuttering one time. It was programming issues. I had a setting turned up to high.
And the other time it was a Stuck brush