Hi Steve,
Some engines have the fuel cut off solenoid in the carby.
The coil load testers I remember were for points ignition where you could get to the wires, not sure if they
would work with the electronic coils as you can't get to the wires when the coil is completely molded in
plastic.
The only other thing I usually do is when fitting a coil is to get some sand paper and sand the metal core
of the coil where it mounts onto the alloy on the motor and clean the alloy where the coil touches the motor with sand paper,I usually also clean under the heads of the 2 coil bolts with sand paper and clean on the coil where the underside of the bolts touch the coil but after sanding all those parts to get a good earth wipe all sanded parts with a clean rag before assembling as sand paper has silicone which is a poor conductor and wiping with the rag takes away the silicone, you could wire brush the threads if they are dirty too
May have just been a bad earth of the coil.
Cheers
Max.
