Your carburetor is an integral part of your lawn mower engine. Keeping it running smoothly is of great importance for the reliable performance of your lawn mower. In this article. We’ll give a step-by-step guide on Briggs and Stratton carburetor replacement on a lawn mower.

Signs You Might Replace Your Mower Carburetor
A dirty carburetor is one of the most common causes of lawn mower problems. People usually replace spark plugs, buy new fuel filters and fiddle with settings, only to find the real culprit is the carburetor all along. Here are the signs you need to clean or replace your carburetor.
- Hard starting
- The mower starts then dies
- Rough running
- Loss of power
- Black smoke
- Surging engine
- Poor fuel efficiency
However, any single symptom of the above doesn’t necessarily mean a dirty or worn carburetor. If three or four signs occur at one time, it probably points to the carburetor.
Step-by-Step Guide on Briggs and Stratton Carburetor Replacement
The main function of a carburetor is to blend air with fuel to form a combustible mixture that ignites in the cylinder to drive the piston. If the carburetor is clogged or heavily damaged, you should replace it with a quality carburetor. Here is a step-by-step guide on lawn mower carburetor replacement. This is a general guide to replace the carburetor on common Briggs & Stratton engines that power Craftsman, Toro, MTD, Husqvarna and Troy-Bilt walk-behind mowers.
Step 1: Disconnect the Spark Plug Wire
You can choose a place that is well-ventilated to disconnect the spark plug wire from the spark plug.
Step 2: Remove the Air Filter Housing
This step involves three actions: release the catch and pull the air filter cover off; remove the air filter and the screws from the air filter base; release the breather tube and pull off the air filter base.
Step 3: Drain the Fuel Tank
You can position a shop rag under the fuel tank to catch spills. Then, find a fuel container and place it under the gas line connection to the fuel tank. Drain the gasoline into the container by releasing the spring clamp and disconnecting the fuel line from the gas tank. In the meantime, you should wipe up any spills in order not to get your workplace oily and messy.
Step 4: Remove the Blower Housing
You can release the starter rope from the mower handle and remove the screws from the housing, so you can pull the blower housing off the engine.
Step 5: Remove the Carburetor
To remove the carburetor, you should separate the carburetor mounting bracket arms to release the carburetor and disconnect the carburetor from the adapter. Then, disconnect the governor and choke linkage rods and remove the carburetor. After that, release the fuel line spring clamp and pull the fuel line off the carburetor.
Step 6: Install the New Carburetor
Push the O-ring into the outlet port of the new carburetor and install the retainer on top of the O-ring. Then, connect the fuel line to the new carburetor and secure it with the spring clamp. Hold the carburetor over the mounting brackets and connect the governor and choke linkage rods. Push the carburetor into the bracket arms, the outlet port fully onto the carburetor adapter and the air cleaner gasket into the channel on the carburetor inlet.
Step 7: Reinstall and Reconnect Everything
The last step is to reinstall and reconnect everything you dismounted, including the blower housing, the fuel line, the air filter housing and the spark plug wire. Now, you have replaced your mower carburetor yourself.
Common Mistakes to Avoid After Briggs and Stratton Carburetor Replacement
Whether you just clean your carburetor or replace it with a new one, here are common mistakes to avoid to extend the life of your carburetor and help prevent costly repairs.
- Ignore early signs of a bad carburetor and allow it to deteriorate, like hard starting, slight roughness, until the mower stops entirely.
- Keep running on old fuel after cleaning the carburetor. This can cause the deposit to build up quickly again.
- Clean the carburetor only but skip the air filter. A dirty air filter can lead to the same symptoms. See how to clean and replace air filter for your mower here.
Final Words
The carburetor is essential to the engine of your mower. A dirty carburetor can cause a series of lawn mower problems. If the basic cleaning can’t fix the problems, or you have limited time to rebuild it, replacing the old faulty carburetor is a wiser option, which can save you from headaches, money and time. FridayParts provides a vast range of lawn mower carburetors, rebuild kits, and related parts, such as air filters, spark plugs and more. Once you’ve cleaned or replaced the carburetor, do watch for early signs. Now go get that mower running clean. You’ve got this.
