BG,
I have replaced the starter on 3 different occasions and the same thing happens each time. Do you think that maybe the ignition is keeping the solenoid engaged therefore causing the fire?
simple answr is to take trigger from solonoid lead out of circuit.connecting this lead temporarlarly to bat+ will spin and start motor (ign on),if then machine runs ok & no flames,its safe to assume ur guess is right.a simple push button switch would run for ever and would bypass ant harness faults.