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The carburetor is one of the essential parts of your lawn mower that requires regular cleaning for it to work efficiently.
Grass clippings, twigs, debris, and dirt will find their way into the carburetor after a few uses, clogging the air and fuel passages.
Most owners bring the equipment to a professional, but once you learn how to clean carburetor on lawn mowers, you’ll find that it isn’t a complicated process.
Allow us to guide you through the steps and learn an essential skill that will save you time and money.
When To Clean Your Lawn Mower
Before learning the proper steps to clean your mower, you must know when it’s time to do so.
Generally, you must clean regularly-used mowers twice a year, while once a year for those that aren’t used as often.
With that said, some tell-tale signs that can indicate your mower already needs cleaning are:
- Trouble starting the engine
- Engine starts but stalls
- Engine runs roughly while you mow
- Black smoke coming out of the mower’s muffler
- Increased fuel consumption
However, the signs listed above aren’t specific to dirty carburetors; they may also be due to insufficient fuel, dirty fuel, and dirty filters.
How To Clean Carburetor on Lawn Mower
Once you determine that the carburetor is dirty or it’s your mower’s regular cleaning schedule, take it to a well-ventilated area.
Make sure you open the windows and doors if you’ll work in your garage since fuel has bad health effects, especially when inhaled.
Once you’re ready, follow the steps below. You may also take a photo or video, especially for the disassembling steps, to ensure you re-assemble the mower properly after cleaning.
Step #1: Remove the Outer Casing
The procedure for removing the outer casing will depend on the lawn mower model.
Nonetheless, here are what you need to do:
- Loosen the screws to remove the cover, revealing the internal parts.
- Carefully remove the air filter cover, followed by the filter itself, and then finally, the air filter housing, exposing the carburetor.
- Check if the filter is dirty or requires replacement. If it requires cleaning, wash it with hot water and mild detergent. Rinse with warm water, allow to dry thoroughly, and wipe with fresh motor oil.
Step #2: Detach the Carburetor
This step is the top reason many lawn mowers are scared of cleaning the equipment’s carburetor on their own.
The carburetor is firmly bolted in place, but it actually comes off easily once you unbolt it.
To do so, follow these steps:
- Place a catch basin below the engine.
- Take your nut driver and unbolt the carburetor from the lawn mower.
- Slowly drain the fuel line into the catch basin to prevent any mess in your working area.
- Detach the mower’s throttle linkages and choke from the throttle lever, ensuring the spills drip into your catch basin.
- Wipe any spills with a rag before proceeding.
- Gently slide the carburetor off its mounting bolts.
- Inspect the carburetor for any signs of corrosion or damages. If so, consider replacing instead of cleaning.
Pro Tip: If the fuel doesn’t spill, something might be blocking the fuel line, so inspect and troubleshoot.
You can do so by blowing air into the line with the help of the carburetor cleaner’s tip.
You may also insert a thin wire, but take precautions to ensure you don’t puncture the line.
Step #3: Unbolt the Bowl
Another essential part of your lawn mower is the float bowl since it helps maintain the fuel at a constant level.
It has a cylindrical shape held by one or two bolts and nuts.
To unbolt and clean it, here’s what you need to do:
- Clean around the bowl using your carburetor cleaner.
- With a wrench, carefully loosen the nuts, release the bolts, and remove the bowl.
- Take a paper clip or wire and poke inside the hole where you removed the bolts to dislodge any dirt or debris present. You may also spray carburetor cleaner into the hole.
- In case the bolts and nuts have rust, scrape them off using sandpaper and then spray them with carburetor cleaner. Set aside for later use.
- Inspect the bowl for any damages or the presence of too much dirt. If so, consider replacing it. If not, scrape off the dirt or rust and then clean with carburetor cleaner.
Step #4: Disassemble Other Parts
At this point, you’ll find that the carburetor has many smaller parts that you need to take apart to clean everything thoroughly.
Here are the steps that you need to take:
- Remove the pin attaching the float to the carburetor, which will allow the release of the needle that you must replace.
- Fully disassemble your mower’s carburetor by unthreading the screws, releasing the base and primer bulb.
- Remove the metering plate, diaphragms, and gaskets.
- Consider replacing any parts that you think are nearing their death.
- Poke the inside of the holes with a paper clip or wire to dislodge any dirt or debris.
- Spray all the ports with a carburetor cleaner to remove any remaining residue and dirt.
- Allow the parts to air dry.
Step #5: Inspect
During the disassembly and cleaning process, you might have detached some wires or other lines.
Thus, give your mower a quick inspection with the help of a flashlight.
Adjust whatever has been moved and connect whatever has been disconnected.
Step #6: Re-assemble and Re-attach the Carburetor
Now that all the cleaned parts are completely dry, damaged or almost-dying parts are replaced, and the mower is inspected, it’s time to re-assemble and re-attach your carburetor.
That is, doing the disassembly process in reverse. You can use the photos or videos you took as a guide.
Nonetheless, you can follow these steps:
- Position the gaskets, diaphragms, primer base, metering plate, float, and needle.
- Re-install the bowl.
- Gently slide your mower’s carburetor onto its mounting bolts.
- Re-attach the throttle linkages to the lever and the fuel line to the newly attached, clean carburetor.
- Re-install the air filter, cover, and housing.
- Re-install your lawn mower’s engine cover.
Step #7: Test Your Lawn Mower
Now that you’re done cleaning your lawn mower’s carburetor, it’s time to put it to the test!
Drain the fuel tank and refill with fresh gas.
Start your mower and start mowing!
A Clean Carburetor Equals a Well-Functioning Mower
With the carburetor’s critical role in the lawn mower’s function, keeping it free from dirt and debris that can clog its parts will ensure it will work as expected.
Not only that but cleaning it also allows you to replace the parts that are nearing their death.
That said, the secret to how to clean carburetor on lawn mowers is getting to know your equipment by heart.
Review your owner’s manual and familiarize yourself with the parts.