Step 1
Locate a gap gauge or feeler gauge.
Step 2
Clean the spark plug. If it is new, this shouldn't be an issue; however, if you are checking a spark plug that is currently in the vehicle, it might be dirty on the contact points. Never use abrasive materials to clean a spark plug.
Step 3
Measure the existing gap of the spark plug. Using your gap gauge or feeler gauge, run the tool through the electrodes to determine the measurement. Take note of the measurement and compare it to the recommended setting listed in the owner's manual.
Step 4
Make any needed adjustments. Select the correct measurement on your gap gauge or feeler gauge. If you can’t get the correct feeler gauge through the gap, the gap needs to be widened. If the tool runs through the gap without touching the electrodes, the gap is too big and must be narrowed.
Use your spark plug gap tool to adjust the gap. Gently bend the ground electrode in to narrow the gap or bend it out to widen it.
Be very careful when making adjustments. Don't bend the electrode more than a few fractions of an inch. It is durable but isn't designed to take a lot of pressure. Also, take care not to hit the center electrode. If you snap off the bottom electrode or damage the center electrode from excessively prying on it, you'll need a new spark plug. Precious metal iridium or platinum center electrodes can be very delicate when it comes to prying them. It is important to use the proper spark plug gapping tool.
Step 5
Check the gap again. Repeat the adjustment process until the tool fits closely between the electrodes.
Consequences of Incorrect Spark Plug Gap
FAQs
This spacing is pivotal, dictating the spark intensity, which is crucial for efficient combustion. Vehicle manuals provide the ideal gap, which usually ranges between 0.028″ and 0.060″. If you're unfamiliar with how to gap spark plugs or use pre-gapped spark plugs, it's always good to consult with professionals.
Where can the correct spark plug gap distance be found __________? ›
True, the spark plug gap is indeed the distance from the center electrode of a spark plug to the grounding tip. The gap between the electrodes in an automobile engine's spark plug is typically around 0.060 cm. To produce an electric spark in a gasoline-air mixture, a significant electric field must be achieved.
What happens if you don't gap spark plugs correctly? ›
The incorrect plug gap for your engine can contribute to a high rate of misfires, loss of power, plug fouling, poor fuel economy and accelerated plug wear. It is always best to check the gap against the manufacturer's specifications.
What happens if a spark plug is gapped too wide? ›
If spark plugs are gapped too wide, the ignition spark loses some of its strength as it crosses the spark plug gaps. This can result in engine hesitation.
What is the proper gap? ›
Finding the Proper Gap Setting
The gap setting is different for each vehicle but most are somewhere between 0.028" and . 060". Consult the owner's manual or Champion ® catalog to find the recommended setting for the vehicle you're working on.
What is the spark plug gap on a 5.7 350? ›
The Chevy 350 spark plug gap is 0.035 inches.
Make sure the spark plugs are clean and free of dirt and other debris. Use your feeler gauge or gap gauge to measure the current gap.
Is it better to have a bigger spark plug gap? ›
The larger the gap, the more voltage is needed to jump the gap. Most experienced tuners know that increasing the gap size increases the spark area exposed to the air-fuel mixture, which maximizes burn efficiency. For this reason, most racers add high-energy ignition systems.
Do NGK plugs need to be gapped? ›
While most NGK spark plugs are pre-gapped, there are occasions when the gap requires adjustment. Care must be taken to avoid bending or breaking off the fine-wire electrodes. NGK recommends a round wire-style or pin gauge gap tool to measure the gap.
Do iridium plugs need to be gapped? ›
Iridium Power Gapping Tips
Should you decide to re-gap your Iridium Power plug, use extreme caution as improper gapping may damage or destroy the Iridium center electrode or porcelain center.
Does gapping spark plugs give more power? ›
Also known as "side-gapping" in a racing or extreme high-performance engine, this improves the flame kernel efficiency and propagation through the combustion chamber. There are at least four reasons why side-gapping spark plugs can be beneficial for increasing both power and mileage.
The spark in a spark plug jumps across the gap between the spark plug's two electrodes (Figure 1). The size of this gap can affect the spark's timing, or when exactly the spark occurs during the piston's stroke.
Is a larger gap on a spark plug better? ›
The larger the gap, the more voltage is needed to jump the gap. Most experienced tuners know that increasing the gap size increases the spark area exposed to the air-fuel mixture, which maximizes burn efficiency. For this reason, most racers add high-energy ignition systems.
What is the spark plug gap normally kept? ›
The recommended spark plug gap range varies depending on the type of engine and the manufacturer's specifications. However, in general, the spark plug gap range is kept between 0.3 to 0.7 mm.
