VEHICLE LURCHES FORWARD UNCONTROLLABLY. THROTTLE RESPONSE IS EXTREMELY ERRATIC. THIS CAUSED INEXPERIENCED RIDER TO LOSE CONTROL AT A LOW SPEED AND WAS THROWN FROM VEHICLE AS IT WENT OUT OF CONTROL ONTO THE SIDEWALK. FUEL TANK WAS NEARLY FULL. CONTINUED RIDING EXHIBITED EXTREMELY ERRATIC THROTTLE CONTROL. VEHICLE IS VERY UNPREDICTABLE. *TR