Internal combustion engines (ICE) are powered by a series of small explosions that occur inside your engine. These explosions require fuel, air, and, finally, a spark, which is what the spark plugs are responsible for.
Despite their simplicity, spark plugs are critical to the continued functioning of your engine and understanding how they work, when and how to replace them, and the different types of spark plugs that are available will help you maintain your engine.
Each cylinder has its own spark plug and a piston. The one exception to this is a Hemi which has two spark plugs per a cylinder because Dodge has to be extra like that. For every other engine type, you’ll know how many spark plugs you will need because it will match the number of cylinders that you have.
When the piston moves down, it draws in fuel and air. When it goes up, the piston compresses that air-fuel mixture. Then, the spark plug creates a spark, and that spark ignites the air/fuel combo and pushes the piston back down, giving your vehicle power. The crankshaft turns, and the piston pushes up, forcing the exhaust out, and then the piston goes back down, pulling in more fuel and air. This process is ongoing, and when it’s working together, smooth and efficient.
Despite their relatively small size, spark plugs are a critical component of your engine and need to be in working order for your Motorcycle to run correctly.
REPLACING SPARK PLUGS
Getting peak fuel efficiency and performance out of your engine requires functioning spark plugs. Having spark plugs that misfire can cause a rough idle, lack of throttle responsiveness, and many other problems you don’t want to deal with.
Though most people have noticed that manufacturer’s recommendations for oil changes tend to be on the low side, the opposite is true for how long they expect your spark plugs to last. Manufacturers tend to have an optimistic opinion of spark plug’s longevity that just doesn’t line up with most people’s actual experiences.
Tools
- Compressed Air
- Torque Wrench
- Gap Gauge (and your vehicle’s gap setting)
- Anti-Seize Lubricant
Drive your Motorcycle for a few miles, then stop and wait for the engine to reach about room temperature. This will help with a smooth removal. Disconnect your negative battery terminal, and then clean away any grossness that’s accumulated around your plugs. You don’t need to clean until shiny, you just don’t want anything to fall in while you have your spark plug out.
Disconnect electrical connections, remove the bolt, and then gently pull up on the coil pack. You can wiggle lightly if it gets stuck. Then use a spark plug socket to loosen the plugs. Then, use the spark plug boot to reach in and pull the spark plug out gently. Be warned that sometimes spark plugs will break off and then you’ll need to get a plug extractor. It’s just easier to not break it.
Now, it’s time to take a look at your spark plug.
Installing the New Spark Plugs
Let’s be honest. First of all, Motorcycles have their spark plugs in different places based on make and model. Some of them would require an elite gymnast to access. Mechanics have the correct tools to reach these spark plugs and they’re cheaper than a visit to a doctor because you got your arm stuck reaching somewhere you shouldn’t have been.
But, if you can see all of your spark plugs and you’re confident that you can reach them without bending inappropriately, then you can change your own spark plugs.
Gap gauges can be picked up inexpensively at almost any hardware store. Using the gap gauge, you can check the distance between the electrode and the arm. It should be a precise fit, so the wire on the gauge should touch ever so slightly, but not so much that you can’t easily pull it out.
Applying anti-seize lubricant to the base of a new spark plug
Then, apply a thin layer of anti-seize lubricant on the threads of your spark plugs, screw them in, and torque them to manufacturer specifications. Be gentle during this process. Though most people note that installing spark plugs is almost impossible to mess up, the one way you can is by over tightening and breaking a spark plug, especially if it goes down in a cylinder.
To get the boot back on correctly, many recommend using a small amount of dielectric grease. It certainly helps it to go on easier and it may help prevent misfires.
Then, reinstall the coil packs, re-bolt, and reattach electrical wires. Repeat process for each spark plug.
When you’re finished, don’t forget to reattach your battery and then go ahead and start your Motorcycle up. With new spark plugs, you should notice an immediate improvement in the way your vehicle functions. Most people agree that changing your own spark plugs is an easy part of Motorcycle maintenance that requires few tools, but if you’re uncomfortable there’s nothing wrong with asking a professional to do it for you. But hopefully, now that you know more about how spark plugs function and what to look for, you’ll know when to change them and what to look for in your next set of spark plugs.