Where is the Carburetor on a Lawn Mower? (Every Mower)
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I’ve always enjoyed using my cordless walk-behind push mower – no pesky cord to haul around and no gas to fill in the tank. But when I need a surge of power to complete larger jobs with ease, my go-to choice undoubtedly is my robust 140cc Briggs Stratton gas push lawn mower.
The downside however of using a gas-powered lawn mower is maintaining the many different parts like the air filter, spark plugs, hoses, and several other parts under the hood including the lawn mower carburetor.
Of all these aforementioned parts, the lawnmower carburetor is often the most overlooked but is in fact one of the most important parts of a mower just like a lawn mower engine that requires a fair bit of maintenance including annual maintenance.
What is a LawnMower Carburetor?
All gasoline-powered lawnmower engines are fitted with a carburetor. Similar to your car or truck engine, a carburetor helps run the small engine of a push lawn mower, self-propelled lawnmower, or riding lawnmower.
What Does a Lawnmower Carburetor Do?
The only goal of a lawnmower carburetor is to ensure that the right mixture of fuel and air enters the engine cylinder to trigger combustion.
This component of a lawnmower adjusts the balance of air and fuel based on myriad different factors including the amount of time the engine has been running, your speed, and the type of terrain you’re mowing.
Unlike automobile systems, a carburetor of a lawnmower doesn’t contain any throttle butterflies (a pivoting flat valve controlled by the gas pedal) but contains a rubber-type push bulb, through which fuel is primed when the bulb is depressed several times on a push-type lawnmower.
The fuel from the fuel tank flows through the bulb via a hose into the carburetor, which typically allows gas to drip into the carburetor bowl.
The engine creates a suction on the carburetor which mixes the gasoline with air at a specific ratio. After the carburetor has been primed, you can use the pull rope to start the engine.
What Does a Lawnmower Carburetor Look Like?
Most lawnmower carburetors look similar, with a small metal component complete with levers and springs and a distinct bowl shape under the carburetor body.
The carburetor float bowl accommodates the fuel and provides a continuous supply of fuel to the carburetor mixture as required.
The float bowl of a lawnmower carburetor can be drained with either the onsite drain bolt or screw without dismantling the whole system.
Where is the Carburetor on a Lawnmower?
This depends on the type of lawnmower you’re using, whether push, self-propelled, or riding lawnmower.
Where is the Carburetor on a Push Lawnmower?
Just as the name suggests, a push mower is any type of mower that you walk behind and push. The carburetor of a push mower is tucked away neatly behind the air filter at the side of the machine.
If you can locate the air intake filter or air filter of a push lawn mower, you’re one step closer to finding its carburetor. Depending on the machine, the air filter of a push mower is typically encased within a metal or plastic shroud and secured by a screw or with snap fittings.
Where is the Carburetor on a Riding Lawnmower?
The carburetor of a riding lawnmower is located just beneath the hood under the engine blower assembly so you’ll have to undo the hood latches of the engine hood to access it.
Similar to walk-behind mowers, the carburetor of a riding lawnmower is located behind or below the air filter, so once you remove the filter, you can spot it easily.
Signs a Lawnmower Carburetor is Dirty or Damaged
Old Gasoline
Old gasoline is the biggest enemy of a lawnmower carburetor regardless of the type of engine whether Briggs Stratton or brands including John Deere.
Your lawnmower will still run on old gasoline but it won’t offer the same top-notch performance that you’re used to.
This is why it’s highly important to empty the lawnmower gas tank when storing the machine for the off-season because old gasoline creates what is known as shellac in the fuel system.
This shellac blocks the inner workings and the air and fuel jets in the carburetor, which further prevents the fuel and air from passing through it.
A clogged gas line can be detrimental to the entire fuel system including the fuel filter, and mower air filter, and may even emit black smoke, which indicates that the machine is “running rich,” or burning too much gasoline.
The only solution for a gummed-up carburetor is a thorough cleaning, which involves removing the carburetor – a task you can do at home rather than visiting a lawn mower engine repair shop.
How to Get Rid of Old Gas in Lawnmower?
Before getting rid of the old gasoline from the lawnmower, check to see if it’s contaminated by pouring some in a glass container, pouring some fresh gasoline in another container, and then comparing them alongside.
If the old gasoline is darker or has a sour smell than the fresh gas, it is probably losing or has lost its efficacy.
Ideally, it’s best to get rid of the old gasoline from the lawnmower completely, but you can try diluting it with fresh gasoline to see if the performance improves.
You can transfer the old gasoline from the machine with a funnel into a jerry can or plastic can jug.
Engine Won’t Start
There could be several reasons why your lawnmower engine won’t start, most notably a dirty air filter, loose, dirty, or disconnected spark plug, and/or fuel not reaching the engine, which may be caused by a faulty carburetor or fuel filter.
If you’ve cleaned the air filter and checked that the spark plug and spark plug cable are connected securely, and you’re still facing the issue, making a few adjustments to the carburetor may help.
There may be many issues with the carburetor such as it’s dirty, the diaphragm is cracked or distorted, and/or it’s simply not getting the proper mixture of air and gasoline.
Your lawnmower’s carburetor and engine are protected against debris, dirt, and grass clippings by air filter guards. It is always a good idea to ensure they are clean and in perfect working condition:
How to Perform Lawn Mower Maintenance?
Maintaining your lawn mower will improve both its performance and service life. Lawnmower maintenance can be carried out at any time of year but the two best times are before the first mow of the season and at the end of the season when it’s time to retire the mower.
Many people choose to take their mower to a professional repair shop for maintenance but these simple checks and fixes can be performed in the comfort of your home.
Since every lawnmower model is different than the other, it’s best to refer to your owner’s manual for maintenance instructions but here are some common tips to keep your mower in tip-top shape.
Replace the spark plug
Removing the spark plug ensures that the mower doesn’t accidentally start. A lawnmower spark plug should be changed every mowing season, after 25 hours of use, or if the mower won’t start.
- Start by disconnecting the spark plug lead.
- Clean the area to prevent any debris from seeping into the combustion chamber when you remove the plug.
- Use an appropriate spark plug socket to remove the spark plug.
- If there are any light deposits on the plug, clean them with a soft cloth.
- Replace the plug if there are any damaged electrodes.
Change the oil
Make sure to replace the oil with the right type of lawnmower oil, but 10W30 is the grade suitable for most lawnmowers.
Drain the fuel tank
If your lawnmower won’t start, the common culprit is old gas. Lawnmower gas can go stale and lose its volatility in as little as 30 days and leaving gas in the tank when not in use can eventually corrode the fuel tank.
Remember to drain the fuel tank at the end of each season and refill it in the spring, and take all the necessary precautions while performing this task.
Clean the mowing deck
The mowing deck is perhaps the most used component of a mower but is also the most overlooked when it comes to cleaning and maintenance.
It’s a good practice to clean the mowing deck every time you finish cutting the lawn. Dirt, cut grass, and debris can accumulate onto the area above the blades, aka the mowing deck, and once it dries, becomes incredibly hard and difficult to remove.
You should perform a thorough mower deck cleaning at the end of the growing season, which entails removing the spark plug and cleaning the mowing deck and blades thoroughly.
Check the tires
Regardless of the type of mower, whether walk-behind mowers or riding lawn mowers, it’s important to check the tires to ensure they’re in good condition and are free from chips and damage.
Here’s an informative video on how to remove a lawnmower carburetor and the steps to maintain and repair a lawn mower: