Toro Lawn Mower Spark Plug Size: Solved!

toro lawn mower spark plug size

A Toro lawn mower with the accurate size of spark plug is essential to provide the engine sufficient sparks to function. I hope you are getting my point that a wrong size spark plug can be a great hazard for the whole lawn mower.

But, have you wondered when you should replace the Toro lawn mower spark plug? 

The Toro lawn mower should be changed when the engine doesn’t start, misfiring of engine is observed, and the engine shows a rough run.

However, your Toro mower and its model will decide which size spark plug is suitable for it. Luckily, you landed on the right space as it carries the Toro lawn mower spark plug size and many more.

Stick till the end to gather the in-depth trifles.

Quick Overview: Toro Lawn Mower Spark Plug Size

Aren’t you already impatient to know the sizes?

Well, I can relate with you as it is such a crucial and unavoidable matter. For better assistance, I have listed the Toro lawn mower spark plug size here for you.

So, let’s take a glance at the list.

SerialSpark Plug ModelSize
1Toro 3827021 Inches
2Toro BPMR4A20 Inches
3Toro BPR6HS30 Inches

Extended Discussion: Toro Lawn Mower Spark Plug Size

Now that you have seen the Toro lawn mower spark plug size, you must have got a few ideas. But, there is still a lot waiting for you to catch them.

Without understanding the spark plug sizes and why there are different plug models, you can not choose the accurate one for your Toro lawn mower.

So, let’s get started as you will find all these answers in this segment.

From the table, you can see the sizes of Toro spark plugs and they can come in other sizes, too. But, these three sizes are the mostly used plugs in Toro lawn mowers.

No matter if you have a riding lawn mower or push one or the walk behind lawn mower, they are the ultimate spark plug sizes.

Though Toro lawn mowers also use spark plugs from other brands, I prefer their self-manufactured spark plugs. It is because they are compatible as well as trustworthy.

How to Know the Size of the Spark Plug? 

Though I have mentioned and described the Toro lawn mower spark plug size, you can still have confusions. Well, it is so common to all and I faced it, too.

Gladly, there are some ways to reach the appropriate size and following them won’t let you down.

Therefore, let me drive you to these methods one by one.

Method 1: User Manual

The user manual that is given with the Toro lawn mower had the info about the spark plug. No other methods are as easy as this one.

It is because the manual carries the correct size of spark plug for a particular engine and lawn mower.

Method 2: Measuring the Thread

If you are unable to find the manual, you have to go this way. The spark plug has a thread and measuring it will tell you what the size of the spark plug is. Thus, do it carefully to make it done.

Method 3: Visiting a Store or Contacting a Dealer

In case you do not have the manual and failed to measure the thread, a simple way is still left. You just have to take out the spark plug and take it to a store. The storekeeper will guide you with the required one.

Also, telling a dealer about the spark plug model or your engine model is an efficient manner. He will surely provide you the spark plug of the needed measurement.

When to Replace the Spark Plug?

There are some signs that will tell you that the spark plug needs replacement. Observing them and inspecting the plug for step ahead assurance will assist you in making the wise decision.

I prefer not to change the spark plug just by assuming and just because it is old or the mower has it for a longer time. What you should do is notice the signs of a bad spark plug and take measures to change it.

However, check out the signs listed below with details.

1. Engine Doesn’t Start

A faulty or bad spark plug shows its first sign with the engine. When it stops generating new and regular sparks, the engine fails to start. It is because the combustion process can not be completed without sparks.

2. Misfiring Engine

A misfiring engine is a significant and serious sign of a weak spark plug. As the plug tends to work slower than before, there can be engine misfiring sometimes.

3. Engine Shows a Rough Run

If you are riding the mower and experiencing the engine is running roughly, the spark plug is at fault. When the spark plug malfunctions, its continuous job of delivering sparks gets interrupted.

As a result, the engine gets sparks for a moment and fails to get them just after that, and thus, rough running is seen.

What Happens if the Spark Plug is Wrong Sized?

Answer: In case the spark plug you purchased is of wrong size, it may not fit in the gap due to being smaller or bigger. As a result, it will fail in producing sparks and the engine will start with difficulty or won’t start due to insufficient sparks.

Do Toro Lawn Mowers Have Spark Plugs?

Answer: Yes, Toro has spark plugs for their lawn mowers. And, purchasing the spark plug from their dealer is the best way to ensure the correct size of it and its compatibility with a particular engine.

How Do I Know What Size Spark Plug I Need?

Answer: You can know the spark plug size simply by measuring the spark plug’s thread. As for an easier way, the user manual has the spark plug size written on it.

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In the end, the fact is any mistake in selecting the spark plug and its size can cost heavier on the Toro lawn mower. For that reason, follow the instructions and the Toro lawn mower spark plug size chart to avoid irregularities.

Moreover, detect the signs of replacing the spark plug and be sure of installing it according to the user manual. Hopefully, everything will be back in place and be normal.

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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