1995 36v ezgo medalist problem

[3491yrennalf]

I purchased a 1995 36v ezgo cart. I think it is a medalist since it has a metal body. It has the f/r selector as a handle under the seat with a rod going to the switch over in front of the controller. I am not sure if it is dcs, series, spex and not sure what brand the controller is. The controller has the solenoid mounted on the controller and there is no tow/maintenance switch. I have new batteries and they test at 41v when charged. The cart jerks hard when you depress the pedal but will not move after the initial jerk-forward or reverse. The solenoid does not appear to have a transitor but it may be hidden. Any suggestions on what I have and what tests to run? Pictures attached of the controller, solenoid .

[3491yrennalf]

I have decided that this is a medalist series cart and I think it is a 4 post Curtis controller with a 6 pin connector. Solenoid does have a transitor. When pedal is depressed the cart immediately jumps at full speed and stops in a second or two, then will not run at all. Afraid it is controller or in pedalbox. Any help will be greatly appreciated.