How to Prime a Lawn Mower Without a Primer Bulb

As I was going about my business yesterday, I saw my neighbor struggling with the mower. He was halfway through mowing the lawn when the mower stopped working. I went up to him and asked him what happened?

My naive neighbor does not quite know about the machines and how to work his way around them. He did not know what made the mower stop working, the guy was worried as some guests were coming and he wanted the lawn to look its best.

I am no expert myself but I decided to help the fella. I checked the mower and saw that the primer bulb was broken. As I was deciding to figure out how to fix it, a friend passed by who had once fixed our lawn mower, I asked him to help. He showed us how to prime a lawn mower without the primer.

Now that I know the whole process so does my neighbor I am going to enlighten our readers as well. Here’s how you can do it yourself.


Can you prime a lawn mower without a Primer?

Starting a lawn mower without a primer? Seems like an absurd endeavor or an impossible one. I was also surprised to learn that one can start a lawnmower without a primer.

What is a Lawn mower Primer? How does it work?

Before I instruct you how to start a lawn mower without a primer, it is mandatory to tell you what a lawnmower primer is and how it functions.

Lawn Mowers tend to have small carburetors which tend to dry up fast and would not take a single drop of gas when the mower is switched on, that’s when a primer comes to the rescue. Primers work by squirting gas/fuel into the engine.

Some Tips on Priming the Lawnmower

Brace yourself, you are about to dig deep in this business. Even though it is easy, It’s always good to prepare yourself for the task.

  • Priming the lawn mower does not take as much as you think. 15-20 minutes for someone who does not know their way around mowers and 5 minutes for a skilled person.
  • When priming without a primer, you would need a starting fluid. It is composed of fuel-related chemicals that take the place of fuel when a machine fails to prime.
  • Use starting fluid in moderation as the spray is quite thick or coarse which may cause clogging and airflow restriction.

There are only two items you need to begin the process, a flat-head screwdriver and starter fluid. If you got these two things, let’s begin the process.

Prepare the Mower For The Task of Priming

Science Direct recommends necessary preparations and check the mower to see if the fuel tank is full.

  • Take the cap off and check if it has sufficient fluid. Refill if needed.
  • Remove the mower’s case and make sure the fuel line, carburetor, and filters are all connected. Everything is where it belongs.

Locate the Air Filter

Find the air filter and I will tell you how to prime the lawn mower with starter fluid.

  • The air filter is generally placed on the side of the engine.
  • Remove the air filters’s cover and be gentle so as not to damage the filter or mower’s engine.

Remove the Air Filter

Most air filters are placed in a way that they block the spray where starting fluid needs to be sprayed. Remove the air filter if it’s obstructing the view or making it difficult to spray fluid.

  • The air filter is usually kept inside the housing. Take off the housing and put out the air cleaner. A screwdriver is needed to detach it from its place.
  • Memorize precisely how it was placed and which side goes in first so you do not have difficulty putting it back.
  • Removal of the air filter allows the sprayer direct access to the air hole where carburetor bore is located.

Starter Fluid

Now, the difficult part is over what’s left is spraying the starter fluid. How hard could spraying the fluid be? a quick heads up, quite easy.

  • Take the sprayer bottle and spray the fluid in the air hole, precisely in the hole from where the air cleaner was removed.
  • Spray a single squirt of fluid not a bit more than that. Excessive spraying will promote build-up, clogging, and airflow restrictions.
  • Starter fluid should be sprayed at a place where it is supposed to, right into the carburetor bore and bowl.

Put the Air Filter Back

Now put the air cleaner back where it belongs for the combustion to happen, to check if the whole process was a success or a failure.

  • If the air cleaner is too dirty, damaged, or counting its last breaths, now is the time to replace it with a new one or an air cleaner with a better condition. If the air cleaner’s condition is good, go with it.
  • Carefully place it back from where you took it, the housing. Secure it in place.
  • Quickly cover it with the case to prevent fluid from evaporating.

Time For The Result 

Now is the time when you would get to know whether the starter fluid worked and did you do your job as you were supposed to.

  • Start the mower, no brainer. Start it by grabbing the pull cord or using an electric starter.
  • Do not expect the mower to be up and running right away. It may need 3 to 5 tries to start.
  • If it didn’t work, spray the last squirt of starter fluid and start the mower again.
  • If the mower starts that means you have successfully primed the lawn mower without a primer.


As they say ‘It’s better safe than sorry, be cautious during the whole process.

  • Wear hand gloves and goggles for your safety.
  • Go through the process with proper care and attention, putting every piece in its place to avoid any unforeseen incidents.
  • Read carefully the user manual of starter fluid, how it works, how much, if it’s inflammable.
  • When priming or repairing, keep children at a safe distance. 
  • Carefully operate screwdrivers.

Priming with a Primer Vs. Priming without Primer? Which one’s better?

No matter who you ask, the majority of people will vouch for primer. It’s safer, built-in, and does not require much effort. Priming a cold lawn mower with primer is a lot easier. Even if it was damaged, just pressing it three times would do the trick.

If somebody wishes to prime the mower without primer, he is going to get himself stuck in a lot of unnecessary work. Spend 5 to 10 minutes whenever one has to start the mower. Removing the case and air filter may damage the engine or filter itself in the process.

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Frequently Asked Questions

What happens if you prime a mower too much?

Over priming comes under the big no-no category. It may cause flooding or clogging. With each attempt, more gas is deposited in the combustion chamber which ultimately makes the mixture too rich.

Is a primer bulb necessary?

Primer bulbs work by depositing the right amount of fuel in the carburetor. It pulls fuel through the fuel lines and makes it reach its place safely. Fix or replace primer if it’s broken or damaged.

How do I start my Lawnmower with a choke?

Here’s how the starting procedure goes for an engine with a choke:
– Firstly, close the choke
– Set the START or HIGH position of throttle control.
– Pull the starter cord to see if it starts.
– If it doesn’t, set the choke halfway.

Do all lawn mowers have the primer bulb?

The carburetor in lawn mowers is small in size as compared to the ones found in large vehicles. Modern lawn mowers are operated by engines and the carburetor used on small engines has a rubber or plastic primer bulb. Most lawn mowers have primer bulbs.

Where is the primer button on the lawn mower?

Check the side of the lawnmower engine, that’s the primer’s place. The primer is generally red in color and located right under the carburetor.

Putting it all together, It may sound crazy to some but priming a lawn mower without primer is possible.

It is not difficult, rather an easy endeavor. Often lawnmower has a problem getting started, either cracked bulb, clogged filter, or cold primer, but there is nothing to worry about if you follow the guide mentioned above, you can start a mower without a primer. Good Luck.


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