Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Hello Ben. Thank you for choosing Just Answer. My name is***** will be happy to assist you.
Ben, can you get the brand, and the model numbers for your engine for me please?
The wires from your ignition switch, to your coils, are designed to shut your engine off, when your key is turned to off position. These wires are your kill wires. Both of your kill wires have diodes, to prevent each of your coils, from grounding the other one out, as your engine is running.
The reason you are experiencing a loss of power in your left cylinder, when both kill wires are connected, is because one of your kill wires have a faulty diode.
You will need to test each diode, to determine which one is at fault. You can either replace the faulty diode, or replace the wiring harness for your ignition coils.
We can continue from here. Thanks!