TribredTrikke rebuild

[kstdenis]

I have a three-wheeled Trikke tribred "carving vehicle" as management proudly called it, although I always thought that was a silly name that brought up visions of sharp knives and turkeys. It has the original motor but I switched out the 3-12v lead acid batteries for a bullet battery, same voltage. The original controller died a few years ago and I've tried various new ones with not much success. The latest one works great but the motor dies every 20 or 30 seconds or when I try to accelerate too rapidly. I have to turn the battery switch off and on at the base and then power back on the LCD display to get it to run again. Then everything is great until the same cycle repeats itself in a minute or so. Overheating? I suspect it's something else because when I put it on blocks and run it full speed it never dies. I'm about ready to just get a 10 inch scooter conversion kit but I thought I'd see if anybody had any ideas. A good problem for some of you technicians. Anybody have any ideas? Thanks!
I posted some photos of the way it looks today. I painted it so I wouldn't have to look at the awful green color it was born with.

Kevin