[Solved!] Try Briggs and Stratton Spark Plug Chart

briggs and stratton spark plug chart

Knowing the accurate Briggs and Stratton spark plug size is indispensable to operate the vehicle. But the size will vary according to which type of vehicle you own and what is the model.

But, it is easier to get confused as there are many sizes available for spark plugs. So, what are the mostly seen spark plug gap sizes of Briggs and Stratton?

Though there are many gap sizes available for Briggs and Stratton spark plugs, the mostly seen sizes are SPH 20.6 mm and SPR 12.7 mm and thread size is 14 mm.

Not only this size, some more sizes are described below in the Briggs and Stratton spark plug chart to assist you. A few additional facts are also added to understand the matter.

So, let me break them down for you.            

Quick Overview: Briggs and Stratton Spark Plug Chart

Learning about spark plug gap charts will be easier if you get a rapid idea about it. No wonder, your valuable time will be worth it.

I researched well and formed a whole list of the spark plug size. Why don’t we take a look at the chart?       

NumberBriggs and Stratton Vehicle TypeSPH Size (Spark Plug Hex)SPR (Spark Plug Reach)
1Mower16 mm12.7 mm
2Snowblower20.6 mm9.5 mm
3Chainsaw20.6 mm12.7 mm

What Happens If You Use the Wrong Spark Plug in a Lawn Mower?

Using a wrong spark plug is always discouraged due to some reasons. Learning about them, you will understand why you should avoid it.

Jump into the discussion to see the outcomes of a wrong spark plug.

1. Issues in Installing it

In case you purchase a spark plug of inaccurate size, installing it will be backbreaking. Because the socket size demands a correct size spark plug and you won’t be able to install it.

2. No Sparks – No Starting

A big or small spark plug will not work in producing sparks for the engine. Consequently, due to zero sparks, the mower will face starting issues.

3. Engine Misfires or Stalls

With a wrong spark plug, the engine starts misfiring and sometimes it stalls, too. It occurs when the sparks don’t get delivered within time or in less amount.

4. Harmful to Components

An incorrect spark plug won’t be able to set in its position. And, it results in damaging the socket of the spark plug.

5. Rough Idling

A wrong spark plug can fit in the place but it will face difficulties while providing the required amount of sparks. As a result when the engine runs, you may encounter rough idling.

How Do I Know What Spark Plug My Lawn Mower Needs?

In case the spark plug in your lawn mower is malfunctioning and it needs a replacement. At this moment, you can not just simply get any random spark plug as it won’t match with your mower.

Follow the simple yet effective facts:

• Spark plug types

Spark plug size

Gap size

Thread size

Heat range

Learn more about them from the below description.

1. Spark Plug Types

An interesting fact is various spark plugs come with different materials, features, quality and longevity.

For example, copper spark plugs are recommended for small lawn equipment with low voltage. On the other hand, platinum spark plugs pair well with heavy-duty equipment and have a better endurance.

2. Spark Plug Size

Spark plug sizes vary according to equipment type, model and a few other things. For that reason, you have to take the older plug and match its size while buying a new one.

Also, your equipment model or its user manual will direct you to the size.

3. Gap Size

The gap, where the spark plug is placed has many sizes and it affects significantly in selecting the spark plug. Not all the spark plugs can match this gap.

4. Thread Size

Measure the thread size of your current spark plug as getting a wrong one will invite oil around the plug. So, it also has a great impact in selecting the spark plug.

5. Heat Range

The heat range of a spark plug decides how much temperature or heat it can endure. As the engine temperature rises higher, get a spark plug with more heating range of at least 8 to 10. 

How to Read a Lawn Mower Spark Plug?

Reading a lawn mower spark plug means understanding the signs of different matters by looking at its appearances.

You can catch their indications easily after following the ways described below.

1. Well Working Spark Plug

A well working spark plug is the same as a normal one that has zero touch of damaging signs. Moreover, its electrode is likely to be in brown deposits.

2. Bad Electrode

A bad electrode of the spark plug is an indication that it has served the engine for an extended duration and now, it demands a replacement.

3. Wet

The spark plug can get wet getting in touch with oil or fuel coming from the engine. Never start the engine without letting it warm up for a few moments. Then, the plug won’t get wet.

4. Carbon Fouled

A carbon fouled spark plug will carry soot like black or dry and both the electrode and insulator tip get them. Balance the air and fuel ratio and clean the air filter to get rid of this.

5. Broken or Injured Electrode

While reading the spark plug, a possible chance is to meet a broken or injured electrode. The reason behind it is the wrong spark plug that is unable to be in that space.

Detailed Discussion: Briggs and Stratton Spark Plug Chart

Only a brief idea won’t help you completely. For that reason, you have to acquire more knowledge about spark plug size and apply them in practical experiences.      

Now, we will move to the discussion to learn new facts about spark plug.  

1. Mower Spark Plug 

For avoiding no electricity running through a spark plug, you have to select the correct size plug for your lawn mower. In most cases, the size remains 14 to 16 mm.

Luckily, Briggs and Stratton spark plug will offer you the same size with improved performance. It offers 16 mm of SPH size and 12.7 mm of SPR size.

Don’t worry about the thread size as it is 14 mm. You will be given three choices of spark plug for a lawn mower – platinum, NGK and champion.

What I encountered is platinum stands first, champion in second place and NGK in third place.              

In my opinion, you should recheck the spark plug’s accurate size before purchasing. Briggs and Stratton have their own way to assist you with that.     

2. Snowblower Spark Plug 

Most people become confused about the spark plug size of a snowblower and a chainsaw. It is because their sizes are comparatively too close. However, there are still differences and they are not the same.       

In the case of a snowblower spark plug, its SPH size is 20.6 mm and SPR size is 9.5 mm. This size is also considered a compatible size for most snowblowers.

Briggs and Stratton spark plugs for snowblowers can come in made of three different substances. First, you can choose copper core material which is in the center electrode.

Then comes the platinum series and the champion series. For a better lifespan, they are regarded as the top-notch spark plugs. The thread size is also appreciative for being 14 mm. 

To get the accurate size spark plug from Briggs and Stratton, you can check out your snowblowers user manual or get in touch with its supplier. Fortunately, you will get vast sizes of spark plug in Briggs and Stratton.                       

3. Chainsaw Spark Plug  

For your chainsaw, the spark plug matters a lot. It is because an incorrect one will only lead to malfunction of the chainsaw.

In a standard manner, chainsaw requires a spark plug with 20.6 mm hex size and gap size is. 030 inches. 8 should be its heat capacity. 

Fortunately, you will have all these features in Briggs and Stratton spark plugs made for chainsaws. It keeps the thread size 14 mm to be standard to fit without any hazard.

But, for chainsaws, Briggs and Stratton prefers platinum, NGK and champion spark plugs only. These are super handy and effective to avoid damages.

If you are unable to find your chainsaw spark plug size in the manual or can not contact the supplier, Briggs and Stratton will help you according to the vehicle’s model.                                     

How to Tell if Your Spark Plug is of Wrong Size?

Though we check everything, mistakes can still occur with anyone. In this way, any of us can get confused and pick the wrong size spark plug.

But, you may not find it even while installing the spark plug. However, a few signs are available that will give you hints regarding it.

Let’s grab a glimpse of these signs.          

1. Engine Not Getting Enough Fuel

If you experience that the engine of your lawn vehicle is not working like before, the problem can be the incorrect spark plug.

It won’t let the fuel reach the engine completely and thus, the engine can stop suddenly, too.      

2. Issues in Fuel Combustion

When the spark plug is of the wrong size, it will create issues in fuel combustion. It is one of the common errors in this respect.

As the fuel combustion can not complete the process, the engine won’t have power to operate spontaneously.           

3. Engine Stopping Roughly   

We know that the engine of the lawn vehicle will stop gradually and smoothly with the power off command.

But, it will face rough troubles in stopping if the spark plug is smaller or bigger than required. Thus, you will encounter rough stopping of the engine.    

In such situations, your task is to check your lawn vehicle’s needed spark plug size and get the accurate one to get rid of these issues.

Lawn Mower Good Spark Plug vs Bad Spark Plug

Recognizing the symptoms of both good and bad spark plug can let you know its current condition and its contribution to the mower.

Check out the differences to know them quickly.

1. Engine’s Performance

The performance of the engine will easily illustrate the symptoms of both good and bad spark plug.

• Good Spark Plug

A good spark plug delivers enough spark and the engine runs pretty well.

• Bad Spark Plug

A deteriorated engine performance is the most common symptom of a bad spark plug.

2. Spark Plug Condition

The spark plugs body and surrounding will carry the sign of its situation.

• Good Spark Plug

An effective one will have less or zero appearance of irregularities.

• Bad Spark Plug

The defective one will contain oil deposits, wet fouling, faults in electrodes, corrosion, and so on.

3. Fuel Consumption

The act of fuel consumption is another way to find out on which level the spark plug is.

• Good Spark Plug

A good spark plug generates more spark and the fuel consumption stays balanced.

• Bad Spark Plug

Refilling the fuel tank again and again is a serious issue to check the spark plug.

4. Quality of Acceleration

The quality of acceleration depends mostly on the actions of spark plug.

• Good Spark Plug

The good one has sufficient spark and the acceleration quality remains satisfying.

• Bad Spark Plug

Due to less spark, the acceleration may make the rider concerned.

5. Smell of Exhaust

The smell of exhaust has an indirect relation with the spark plug.

• Good Spark Plug

Exhaust smell will be as usual when the spark plug is functioning well.

• Bad Spark Plug

A bad spark plug doesn’t burn the mixture of fuel in an efficient way and thus, the exhaust will have the smell of gas.

How to Know Which Spark Plug is Compatible with My Lawn Tractor?  

Answer: You have to check the user manual for knowing about the right spark plug compatible with your lawn tractor. Besides, you can contact your supplier with the tractor’s model identity.       

What Spark Plug Should I Use in My Lawn Tractor?  

Answer: To get the best performance from your lawn tractor, installing the accurate spark plug is essential. Otherwise, the tractor won’t get enough power to respond to your command.          

Does it Matter if My Lawn Mower Has a Wrong Spark Plug? 

Answer: Yes, it matters a lot if your lawn mower has a wrong spark plug. It will lead the mower to perform lower than its capacity. It is because the wrong one will affect fuel combustion and reduce the cylinder’s ability.

What is the Right Spark Plug for a Lawn Mower Engine?

Answer: The right spark plug for a lawn mower engine depends on which lawn mower and engine you have. Each of them has a different preference for both the spark plug size and its material. So, check that out in the owner’s manual.

Final Thoughts

No matter which model your vehicle is, you have to know the spark plug size in case the engine is Briggs and Stratton. For making the best use of your spark plug, the right gap size will help you.

I guess from the Briggs and Stratton spark plug chart, you have got a clear and apt idea. Therefore, your spark plug will perform in its full form and the vehicle will run faster and smoothly.

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Scott McFadden

Hi! It's Scott McFadden. I'm obsessed with farming. All my life I grew up around my grandfather and his farmhouse. I cannot put in words how they inspired me to farm. From taking care of cows to looking after our gardens I have learned a lot. It would be a real pleasure if I get to share this with you.

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