Updated at: 30-03-2022 - By: Lucas

While many motorists are familiar with the concept of a spark plug, they may be unaware of the significance of the spacing between them.

It is critical that the gap on your spark plugs is the correct size before installing it in your vehicle.

If you’re installing new spark plugs, you can always utilize a tool to get the job done.

As an example, the following steps will show you how to gap your park plugs:

In order to get a gap gauge of the feeler gauge,

Make Sure Your Spark Plug Isn’t Clogged

Make sure the Spark Plug Gap is the correct size.

Check and Adjust the Spark Plug Gap Dimensions as Necessary

Repeat the Gap Measurement.

You need to be aware that if you don’t verify and correct the gap on the spark plug, you’ll have to deal with issues.

This is due to the possibility of costly ignition issues such as misfires and other problems.

Why Gap Matters?

How To Gap Spark Plugs Without Tool-3

The spacing between the electrodes of the spark plug is an important consideration that should not be overlooked.

Despite the fact that certain spark plugs are pre-installed with the proper gap, this is not always the case. In some cases, they may be too small or too large.

The efficacy of the spark produced is one of the factors affecting the spark plug gap.

Air-fuel mixture combustion relies on the precise spark for achieving the desired results.

if the spacing is substantially smaller than the recommended size, you will notice problems such as engine misses, bad starts, and hesitation of the engine.

Correct Ways To Gap Your Spark Plugs

What Plug Gap Tool Will You Need?

The wire-type gap gauge can be used to measure the gap between your spark plugs, but you can also use a feeler gauge instead. In order to measure the space between the spark plugs, use this method. In order to check the gap size on the spark plugs, you’ll need to put wires of varied thickness between the electrodes. It may also be possible to use a spark plug gap tool.

A feeler gauge can be used in place of a wire-type gap gauge when it comes to gapping your spark plugs. In order to measure the space between the spark plugs, use this method. Wires of different thicknesses will be used to determine how much space is between the electrodes of your spark plugs.

Spark plug gap tool may also be necessary.

1. Get A Gap Gauge Of The Feeler Gauge

In order to get the job done quickly and effectively, these instruments will be necessary. This approach requires the use of a gap gauge and a feeler gauge.

2. Ensure The Spark Plug Is Clean

In particular, if you have been using an outdated spark plug, it is imperative that you clean it. If it has debris on it, your measurements of the gap’s size may be inaccurate.

Cleaning the spark plug using abrasive materials is not recommended. Cleaning is not essential when installing a new spark plug.

3. Check The Size Of The Gap On The Spark Plug

The gap gauge and the feeler gauge can be used to measure the spark plug gap, and you should select the one that gives you the most accurate data.

Running a tool over the electrodes while checking your vehicle’s owner’s manual’s suggested measurements is a simple way to use these.

4. Make The Necessary Adjustments On The Size Of The Spark Plug Gap

If the measurement of the spark plug gap differs significantly from the manual’s recommendation, you will need to make some changes.

You can use the feeler gauge or tap the l-shaped part’s edge to accomplish this.

Using the same tools, you can also widen the gap till you get the desired size in the gap.

There are a lot of sensitive parts in a spark plug, therefore you must be careful when changing the distance.

Damage can occur if you bend them more than necessary. The parts can be damaged by excessive pressure, therefore you may have to buy a new one.

5. Measure The Size Of The Gap Again

After you’ve made all of your corrections, you’ll want to double-check the gap’s size one last time.

In order to avoid damaging any of the spark plug’s components, you should keep repeating this procedure until you achieve the desired result(s).

Watch this video to see how to do it:

How To Gap A Spark Plug Without Using A Tool

How To Gap Spark Plugs Without Tool-2

When it comes to spark plug gapping, you may not have any tools at your disposal. To be honest, you don’t even need a tool to accomplish this.

To accomplish this, simply follow these instructions:

To begin, determine the proper spark plug gap size. This varies from vehicle to vehicle. The owner’s manual of the car has the precise measurement of the spark plug gap. Check the emissions sticker on the swingarm for this information as well.

The coin style gap tool is the next phase. On the outside edge of the coin style tool, you should be able to see the measuring ramp.

Rotate the device between the electrodes until you feel some resistance, then remove it from the electrodes. Note the gauge’s setting, which should be close to the recommended spark plug gap specified in the owner’s manual, and make any necessary adjustments. If the measurements differ from what’s specified in the manual, make the necessary alterations.

To fine-tune the gap, simply tap the plug on the surface with your fingernail. To avoid injuring the spark plug’s components, be cautious when removing the cap.

To avoid damaging the aluminum insulator or the porcelain on the spark plug while changing the gap, you should be careful not to use excessive force.

These are extremely fragile and can be damaged by with the tiniest amount of force.

If you use the ramp to make any form of gap, you should never use it to measure the spacing between your spark plugs. The spark plug could be damaged if you use it.

One further option is to use a hole-gapper, which is not only effective but also reasonably priced.

In the event that the gap is too small, simply slide the ground electrode into the hole.

After that, you can use the inside ridge to make adjustments to the gap until it’s the size you want it to be. As long as you don’t apply too much pressure while changing the spark plug gap, you should be fine.


These two approaches of spark plug gapping are now at your disposal. You’ll learn more about gapping a plug in the next paragraphs. I strongly recommend that you do so.

Do Spark Plugs Need To Be Gapped?

New spark plugs must, indeed, be gapped. That’s because they may be gapped in the plant before shipping, yet a mistake could still occur in the logistics chain.

Before installing a new spark plug, it is recommended that you check the gap and fix it if necessary.

In this case, it is imperative that both new and old spark plugs be gapped before being installed.

Even if you just purchased new spark plugs that say they’ve been gapped on the packaging, you still need to gap them.

Your car’s owner’s manual should be able to tell you what size you need.

If you want your engine to function at its best, you need to be aware of the importance of the spark plug gap size.

What Happens If I Don’t Gap Spark Plugs?

If you fail to gap your spark plugs or do not gap them to the proper dimensions, you will experience problems.

Wrong gapping will have a negative impact on the normal operation of the car engine.

The following are some of the most prevalent symptoms of a faulty spark plug:

You may notice that your engine is running a little rougher than usual. Because of a misalignment of the air and fuel mixture, they may appear to have an erratic engine idle. Consequently, the engine’s combustion and idle will be compromised.

In this scenario, the gap is excessively large and causing the engine to stall. While driving at high speeds, you’ll notice that it regularly stumbles or pauses.

Because of the poor gapping, engine combustion is delayed, leading to a misfire and eventually an engine that misses.

For an engine to function properly, it must have all of its parts in functional order. A spark plug gapping issue could be to blame for a badly performing engine. In order to prevent an incorrect engine combustion, a weak ignition spark, and a delay in the arcing of the ignition spark, the gap must meet manufacturer requirements.

A problem with the spacing between the spark plugs is to blame for the engine’s squealing. If your engine’s combustion is interrupted or delayed while you’re speeding, this is likely to happen.

What Is The Gap Size For Spark Plugs?

A typical spark plug gap is between 0.75mm and 0.8mm in diameter; this is the most common size. The size of the spark plug required may generally be seen on the package.

When driving or even accelerating on the road, the performance of the vehicle’s engine is directly impacted by the size of the spark plug.

What Happens If Plug Gaps Is Too Big?

When the spark plug gap is too large, the engine’s normal operation will be disrupted.

Having a greater distance to travel before firing the spark plug will be the cause of this.

Its heat is dissipated and it becomes weakened as it traverses the greater distance caused by the larger separation.

You’ll notice things like the automobile misfiring when it’s started. In addition, you may notice a few stutters when you try to press the accelerator pedal.

As a result, it will not perform as well as it should because of the huge space between the plug and the combustion chamber.

What Happens If Spark Plug Gap Is Too Narrow?

This reduces the amount of room needed to mix air and fuel when using a narrow spark plug gap. You can find this room between the hot strip and the ground strap.

Because the spark travels a shorter distance and for a shorter period of time, it does not have the necessary area for charge to ignite the mixture of air and fuel.

When the spark plug gap is too narrow, you will notice irregularities such as a miss in the automobile engine, difficulty starting the vehicle, and a rough idle in the vehicle’s engine.

There are a lot of symptoms here that stem from a lack of attention to the air-fuel balance.

This will lead to the aforementioned concerns, such as a car engine that misses and a hesitant engine.

The spark plug will be wet when you remove it for inspection because of the darkness.

The black and moist appearance indicates that the fuel was not completely burned because the gap was too narrow.

How Do I Know If My Spark Plug Is Pre-Gapped?

In the production, some spark plugs are already gapped, but this gap is disrupted by the logistics.

Before using a new spark plug in your car’s engine, make sure to verify the gap.

Using a gap tool, you may determine if the spark plug you purchased has been pre-gapped. The recommended gap size for the new spark plug should be checked first.

The gap can then be run through the gap tool, and if any resistance is encountered, you can gently press on it to lower the gap’s size or utilize the hole to expand it.

You can find the recommended gap size for your new spark plugs in the specifications section of the package.

Assumptions should be avoided, as should any resulting alterations. This could end up costing you a lot of money because you’ll have to buy a new one.

Can Wrong Spark Plugs Gap Cause Misfire?

Misfiring is one of the side effects of incorrect spark plug gaps. The spark will have to travel a longer distance than necessary because of this.

This will cause it to lose its powerful and hot ignition charge, making it unable to start the plug.

As a result, the vehicle’s engine may misfire after it has been started.

As previously stated, a spark plug that is overly large might cause a vehicle to misfire.

Misfiring may not occur if the gap is too short, as the spark will be unable to obtain the heat it needs to function properly.


The spark plug is a part of the engine that is responsible for igniting the mixture of air and fuel.

Ultimately, this leads to a supply of the poor the engine requires. As a result, it must always be in good working order to ensure that the vehicle’s engine performs at its best.

Improper spark plug gapping is one issue that can hinder the spark plug’s ability to perform its function.

The space between the side electrodes of the spark plug is critical to ensuring that the car engine operates at its best.

When the gapping is inadequate, the engine’s performance suffers, especially when the driver tries to accelerate quickly. This might be the case when the gapping is either too large or too small.