I HAVE A XB 500 THE WIRE TO THE BACK TIRE/HUB WORE THRU AND SHORTED OUT/BURNT WIRES INSIDE SO I SPLICED THEM TOGETHER AND GOT POWER TO WHEEL BUT ONLY FOR 3-5 SECONDS AT A TIME FROM THROTTLE-LET UP AT IT WILL GO 3-5 SECOND AGAIN IF WHELL IS STILL SPINNING-THEN JUST SHUTS DOWN AGAIN--ANY HELP-CONTROLLER-MOTER?????THKS