If you need to do a compression test, or crank over the engine with the spark plug leads disconnected it is important that you earth the leads. Failure to do so could result in the failure of the ignition module. I made up a harness, made of heavy gauge wire. Crimped and soldered a tubular wire connector to one end of the wire with 4mm bolt with the head cut off inserted and soldered into the other end of the connector. Cover the connector with a piece of heat shrink with enough of the bolt thread exposed to take a spark plug nut. If your bike is fitted with spark plug wires that require spark plug nuts, acquire four old nuts from discarded spark plugs. Do this four times then insert the other end of the four wires into a wire clamp and solder. You now should have a harness that does 2, 3 and 4 cylinder engines with or without spark plug nuts. If you make 2 harnesses you can do 5, 6 and eight cylinder engines.
Regards Martin.
