1951 john deere a - did a complete tune up, points,
condenser, rotor, cap, wires, plugs and coil. tractor started right up and ran fine for a few minutes then started misfiring and back firing. had a condenser cause these symptoms before, changed it but still misfiring/backfiring. swapped out the coil, tractor started right up and ran fine again for a few minutes then started misfiring and back firing again. have one used but good coil left,but don't want to use it until I know whats causing this.
found a few possibilities on line. 1- altenator overcharging because of bad regulator but wouldnt fuse blow. 2 - to much resistence in plug wires, they are brand new copper/tinned wires. 3 - bad ballast resistor, which are in the coils, i dont see one anywhere.
what would cause this ?? anyone ever have this happen ??
condenser, rotor, cap, wires, plugs and coil. tractor started right up and ran fine for a few minutes then started misfiring and back firing. had a condenser cause these symptoms before, changed it but still misfiring/backfiring. swapped out the coil, tractor started right up and ran fine again for a few minutes then started misfiring and back firing again. have one used but good coil left,but don't want to use it until I know whats causing this.
found a few possibilities on line. 1- altenator overcharging because of bad regulator but wouldnt fuse blow. 2 - to much resistence in plug wires, they are brand new copper/tinned wires. 3 - bad ballast resistor, which are in the coils, i dont see one anywhere.
what would cause this ?? anyone ever have this happen ??