Cart not throttling right

[jwcasey00]

I converted my cart from a 36v to 48v when I changed to solenoid to wires touched and sparked both go to the throttle pedal, one is blue and one is black, but they connect to different post on the solenoid. Ever since this occured my carts run wide open all the time. I mash the throttle pedal and the cart jumps and takes off full force, I have no control of how fast I go with throttle pedal. Would this have something to do with the controller? I have a AXE 650 on a 94 ezgo. Any help would be great.