How To Clean A Carburetor On A John Deere Riding Lawn Mower

There are but very few yard machines that work as hard as a lawn mower.

But not all lawnmowers get the care they deserve, including the maintenance of both the interior and exterior parts. That said, not caring for the critical internal components (like the carburetor) can cut short the life of your mower sooner rather than later.

At least, that’s what happened with my friend, who called me up frantically to seek help for cleaning her non-responsive John Deere mower. And as soon as I asked her to send me a picture of the interior parts, I knew that a clogged carburetor was the culprit. 

Hi! I’m Stacy, and today, I have curated this guide on how to clean a carburetor on a John Deere riding lawn mower. So, let’s get into the deets!

What Causes A Dirty Carburetor?

Most lawn mower owners know that it's the fuel residue that causes a dirty carburetor. And it’s true to a certain extent, as the carburetor is responsible for combining preset amounts of air and fuel before delivering the resultant mixture to the cylinder. So, you’d naturally want to check the air and fuel systems to ensure a “clean mix.”

After operating quite a few lawn mowers through the years, I have learned that there are various other reasons behind a dirty carburetor. And so that you can take necessary preventative measures (if possible), I have listed the common ones below:

1. Clogged Or Broken Air Filter

Although the internal parts of the carburetor can remain largely unaffected even with a clogged filter, there can be a problem if the filter is broken, there are cracks in the gasket material surrounding the filter medium, or the medium itself is punctured. 

In such cases, the dirt may enter the carburetor and damage it. Hence, I’d recommend cleaning it regularly and replacing it as soon as you spot any cracks or damages.

2. Excess Engine Oil

Overfilling the oil reservoir or crankcase can cause the additional engine oil to settle in the carburetor. This accumulated oil layer attracts environmental dirt to hamper the functionality of the carburetor. 

So, if you have noticed excessive or dark exhaust emission upon engaging the mower engine, it may originate from a dirty carburetor.

3. Other Internal Problems

Aside from a poor filter and excess engine oil, other malfunctioning parts like damaged seals, head gaskets and cylinder rings can’t prevent the engine oil from entering the carburetor, eventually attracting dust and debris.

How To Spot A Dirty Carburetor?

Since it’s not very feasible to check the carburetor every time you switch on the engine, here are some telltale signs that will help you spot a dirty carburetor:

1. The Engine Won’t Start

In case the engine is turning over or cranking but not starting with full force, there may be a dirty carburetor behind it. This is because not enough combustion of air and fuel is reaching the engine to provide it with the required force for engine operation.

2. Popping Sounds

Generally, most lawn mowers use a 12:1 or 15:1 air to fuel ratio. But a clogged carburetor can cause an imbalance in this mix, resulting in “popping” or “sneezing” sounds during the intake.

3. Flooded Fuel Bowl

If you have observed a clogged fuel bowl, there’s a high chance that some of the fuel has flown into the carburetor. Not only that, but it can also damage the spark plugs.

How To Clean A Carburetor On A John Deere Riding Lawn Mower?

Step 1

If you have been operating your mower before taking on the maintenance part, turn it off, remove the keys from the ignition and allow it to cool. I prefer keeping it non-ignited for at least the rest of the day after I finish mowing. Once the body is no longer hot to the touch, remove the front engine cover.

Step 2 (Optional)

You will be able to locate the carburetor on the middlemost portion of the engine’s right side (it looks like a black bowl with a small needle valve at the bottom). 

If the engine makes a sputtering noise when engaged, carefully grab the valve, adjust it towards the right and turn it completely towards the left. It’s actually this valve that controls the air intake of the carburetor, and improper air inflow will invariably cause it to sputter.

Re-run the engine to check if the sputtering sound has stopped. If not, repeat adjusting the valve until you achieve adequate air intake.

Step 3

To clean the carburetor, start by unscrewing the fuel cap of the gas tank and find its vent hole, which controls the air inflow into the gas tank. This, in turn, impacts the airflow into the carburetor. Hence, the vent hole should be kept free from excess oil or dirt buildup.

Step 4

Once the vent hole is clean, place a pan or any other container under the carburetor and loosen the nut located on the underside of the carburetor bowl with a socket wrench. If the engine is still somewhat running, some of the gas will drain out, and the pan will collect it.

After the remaining has drained out completely, remove the carburetor nut and dismantle the carburetor. Keep it soaked in a cleaning solvent for a couple of hours until all the dirt and debris has come off. And don’t forget to clean the nut as well.

But if you don’t have much experience with assembling and disassembling machines, I’d recommend keeping the carburetor inside. You can spray the solvent through the air intake for cleaning the carburetor. 

Step 5

Gently wipe the carburetor and the nut with a soft and clean cloth to get rid of the extra solvent and place it back with the help of the socket wrench. Start the engine to check that it's working properly, and that’s about it!

Bestseller No. 1

Gumout 800002231 Carb/Choke Carburetor Cleaner Spray, Carb Intake Valve Cleaner, Cleans Gum, Varnish & Dirt Inside & Outside Carburetor Chamber & Prevents Future Build Up Saving on Fuel Economy 14Oz.

• Helps Overcome Hard Starting, Rough Idling, Stalling, And High Exhaust Emissions
• Quickly Removes Deposits From The Inside And Outside Of The Carburetor To Improve Engine Performance And Fuel Economy
• Cleans Gum, Varnish, And Dirt From Clogged Carburetors And Choke Valves

Buy on Amazon

Bestseller No. 2

Gumout 800002231 Carb/Choke Carburetor Cleaner Spray, Carb Intake Valve Cleaner, Cleans Gum, Varnish & Dirt Inside & Outside Carburetor Chamber & Prevents Future Build Up 14Oz. (Pack of 2)

• The information below is per-pack only
• Helps Overcome Hard Starting, Rough Idling, Stalling, And High Exhaust Emissions
• Quickly Removes Deposits From The Inside And Outside Of The Carburetor To Improve Engine Performance And Fuel Economy

Buy on Amazon

Conclusion