The Club Car Spark Plug for gas 84-91 models on your caddie is the white thing that screws into your cylinder head. It has a little black cap that snaps on its head once installed. From there, a wire connects it to the ignition coil. This unit is what creates the spark. It takes the voltage from the battery and amplifies it into tens of thousands of volts. All of that power gets forced across the air gap on the plug, making the spark happen. In this same system, you have an igniter that works in conjunction with the pulsar coil to time the spark and collapse it so it can repeat itself hundreds of times every minute. These are just the major players. There are several other behind the scene parts that pull their weight in this process too.This golf cart spark plug is quite simple to install, but make sure you have the right tools. Not any socket can take it off. Just because one out of the toolbox fits it does not mean it is going to work. You need a special socket designed not to hurt the Club Car spark plug, on removal. Call Buggies Unlimited and get what you need.