Registered Forum User
 Big Twin
     Posts: 1,099
 Join Date: Dec 2004
 Location: north hampshire
 Mood: is it cos i is a bricklayer
  
    
     this may be a long shot -theres a connector below the tank four wires coming out of the tank somehow the low level light supply  maybe interfering with the power  supply to the pump?its the only thing that i can think of that connects the pump and low level light-otherwise an intermittent fault like you have could be a plethora of things- ignoring the fact it only happens when the light comes on -coils, leaky manifolds, carbs not set up correctly(mixture,balance,throttle valves,cables not operating correctly,blocked jets)timing advancing correctly but i think you may have checked the obvious ones of this list