Where Is Carburetor On Lawn Mower?

Mower carburetor location diagram

Mower Carburetor Location

Mower engines are quite compact and locating components can be difficult, not to worry this guide will identify the carburetor and many other major mower engine components.

A mower carburetor is located behind the air filter on the side of the engine, opposite side to the muffler.

In this post you’ll learn how to locate and identify your lawn mower carburetor and your mower air filter.

Mower air filter

Air filter

Identifying The Mower Air Filter

A mower carburetor lives behind the air filter and is often hidden from view. So first we’ll locate the air filter.

The air filter is positioned to one side of the engine, makes and models differ as to which side of the engine. But no matter what engine or model they all tend to use a black plastic air filter cover. Once you’ve located the cover, finding the carburetor is a ton easier.

Look behind the air filter housing and for most mowers you’ll see a regular type carburetor. A regular type carburetor will employ a metal bowl which because of its shape is easy to identify.

Mower carb

Carb behind the air filter

What Does A  Mower Carburetor Look Like?

Mower gas tank

Standard Carburetor type

Most carburetors look very similar, small metal components with levers and springs and the characteristic bowl shape under the carburetor body.

Carb bowl

Carb bowl

If you had a carburetor in your hand you’d also notice an opening front and back, that’s where the air enters the carburetor and is forced through the venturi drawing fuel from the bowl as it travels on to the combustion chamber.

What I have described is the standard type carburetor, but not all carbs look like this.

A common Briggs and Stratton carburetor fitted to the Classic and Quantum engines is the plastic carb and metal gas tank assembly.

Mower gas tank

B&S carb and tank assembly

This type carburetor is somewhat similar, as it lives under the air filter and employs levers and springs to control engine rpm. However it doesn’t use a conventional gas bowl, instead the gas tank assembly and carburetor work together to perform all the functions of a carburetor.

It’s worth noting the latest carburetor types are plastic, they still live behind the air filter housing and employ levers and springs and a gas bowl. However the bowl may not be as pronounced as the traditional bowl.

Mower carb bowl

Dirt inside the carb bowl

Common Carburetor Problems & Fixes

Carburetors although small and insignificant looking are in fact very sophisticated and crucial to your mower engine performance.

A mower engine requires a mixture of fuel and air in order to run. The ratio of fuel to air also known as the AFR (air fuel ratio) is 14.7 to 1 (written 14.7:1).

The carburetor is tasked with maintaining this ratio, and that’s no easy task. Fuel demands change as the engine cuts grass or idles or traverses up a steep hill, the carburetor needs to make adjustments immediately.

Mower jet Mower jet cleaning

Blocked Jet

If the carb supplies too little gas to the mix, the engine loses power and/or dies. If on the other hand the carb supplies too much gas to the mix, the engine stumbles, blows black smoke and operates at reduced power.

When the ratio is off, it may be the fault of the carburetor, however sometimes it’s not. A blocked air filter will prevent enough fresh air reaching the carburetor, this often results in black smoke and poor performance.

A blocked fuel line or fuel filter will prevent enough gas reaching the mower.

However the most common type carburetor issue is contaminated gas (old, dirty or water in the gas). The next most common carburetor is dirt in the fuel jet and emulsion tube, the jets and tube are tasked with metering the fuel through small holes, as you can imagine when these holes are obstructed, the ratio is off.

The most common repairs I make to mowers in a season is carburetor cleaning. I’ve covered this common repair in this post “Mower stats then dies”, or check out the video library if you need video help, all the most common engines are covered.

Mower emulsion tube

Carb Jet and emulsion tube

Auto Technician and Writer at | Website

John Cunningham is an Automotive Technician and writer on Lawnmowerfixed.com. I've been a mechanic for over twenty years, I use my knowledge and experience to write "How to" articles that help fellow gear-heads with all aspects of mechanical repairs, from lawn mowers to classic cars.