Proper Carburetor Adjustment on Briggs and Stratton Mower

how to adjust carburetor on briggs and stratton lawn mower

Briggs and Stratton carburetor adjustment has a great impact in balancing the fuel and air ratio and their mixture and the RPM or speed of the lawn mower.

However, I guess you are wondering what is the process of adjusting the carburetor on a Briggs and Stratton lawn mower?

Adjust it by making the lawn mower ready, starting with the idle speed mixture, moving to the high speed mixture, resetting carburetor choke linkages, and setting everything back in place.

The in-depth idea of how to adjust carburetor on Briggs and Stratton lawn mower are included in the article. The side effects of not adjusting are also described here.

So, continue reading till the end to learn them.

Process of Adjusting the Briggs and Stratton Carburetor

There can come many times when the carburetor on Briggs and Stratton lawn mower feels the requirement of adjustment.

Though there are a few ways to adjust it, I picked the easier one. It is also very effective and ensures successful adjustment.

So, let me break the steps down for you.

Step 1: Make the Lawn Mower Ready

First, you have to run the Briggs and Stratton lawn mower and give the engine enough time to warm up. After a few minutes, switch off the ignition system that will cool down the engine.

Don’t forget to maintain the position of parking brakes and the neutral position of the drive gear. It will ensure the mower stays in a place without moving.

Before moving forward, if you are not familiar with the carburetor components, check out Briggs and Stratton carb adjustment diagram.

Step 2: Start with Idle Speed Mixture

When you reach the casing of the mower’s, the carburetor is just close to the air filter unit. Remove the air filter and its casing and keep everything in a safe place. Then, clean the carburetor with a cleaner and wipe it thoroughly.

Reach the idle screw placed beside the carburetor and turn it clockwise till the needle of it gets close to the carburetor. Then, rotate it 1.5 times counterclockwise.

If your carburetor has a main jet, adjust its screw the way you adjusted the idle speed screw.

Step 3: Move to the High Speed Mixture

Look for these screws on the opposition of the idle screws. They are adjusted just the way idle adjustment screws and the main jet screws were adjusted.

Move to the throttle and turn it on a fast movement. After that, wait for the engine to slow down and till then, keep rotating the high speed screws clockwise. Then, do the opposite, counterclockwise.

Notice the engine’s sound and stop rotating when you feel the sound is stable. Then, keep the throttle back in its previous position.

Step 4: Reset Carburetor Choke Linkages

Now, keep the throttle again in a fast position and look for the choke linkage. A screwdriver will help you in removing the casing along with the bracket. Be aware of keeping the screw right there and not taking it out.

Then, watch the choke plate to go closer to the carburetor and till then, set the cables. This place is the right one for the cables and you need to secure them right there. To do it, set the bracket alongside them.

The movement of the throttle will show you how the choke plate operates and maintain a medium position for it. Move to the spring connector and tighten it if required.

Step 5: Set Everything Back and Check

In the last step, clean the lines of the carburetor that are the inlets and outlets. Make sure you wipe them well to dry and zero moisture is there. Now, this is time for setting everything back in their accurate place and close the casing.

Finally, go to the ignition switch and turn it on. Keep an eye on the engine’s speed and running quality and see if anything is irregular or not. Hopefully, you have successfully adjusted the carburetor.

What If the Briggs and Stratton Carburetor is Not Adjusted?

It can happen that the carburetor on Briggs and Stratton lawn mower is not adjusted for a longer period and it needs immediate inspection. But, you can forget that or may not understand the indications.

Sadly, there will be more troubles if it is not adjusted. Take a look at the issues that occur at that time and they are described below.

1. Engine Rev Up and Down

When you do not adjust the carburetor, the engine will rev up and down all of a sudden. You may get worried and it is normal for all. As the adjustment is not performed, the irregular idling will lead it to surging issues.

Thus, you notice the engine rev up and down.

2. Mower Runs Roughly 

A bitter truth is ignoring the carburetor adjustment is behind the mower’s rough running. As the fuel and air ratio doesn’t match with the mower’s requirement, it can not run as smoothly as it used to.

So, run to the Briggs and Stratton lawn mower to adjust its carburetor.

3. Mower Fails to Start

I can assume that you know that the carburetor sends the mixture of air and fuel to the engine to start the mower. As a result, when zero adjustments of it are made, it fails to flow that mixture as usual.

You can guess that avoiding the need of the carburetor can result in keeping the mower idle and off duty.

How Do I Tell What Briggs and Stratton Carburetor I Have?

Answer: A Briggs and Stratton engine has model numbers for each component including the carburetor. On the engine model number, you can see the carburetor model and the owner’s manual have it, too.

What Happens When the Fuel Pressure is Too High on a Carburetor?

Answer: The carburetor on a lawn mower having too much higher fuel pressure will direct extra fuel to the engine. As the amount is more than normal, the spark plug can go bad.

What are the Symptoms of Too Much Air on a Carburetor?

Answer: Too much air on a carburetor is not at all recommended for a lawn mower. There will be sounds like coughing or sneezing when the mower is running and it will show a rough run.

Final Words

As I said earlier, how to adjust the carburetor on Briggs and Stratton lawn mower is easier when you know the correct process and the details of it.

As it is working with a sensitive component of the lawn mower, I recommend following the steps respectively. It will ensure no mistakes are made.

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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