How to Clean a Generator Carburetor

The carburetor is among the essential components of a generator. It mixes oxygen and water, thus enabling the generator to convert fuel into power. Gasoline carburetors are designed to take in an exact amount of oxygen for fuel to burn properly. A carburetor ensures that there’s a proper fuel-air mixture. It allows oxygen and fuel into the generator’s engine via the fuel valve. It also mixes them in different proportions as per your power production requirements.

For your generator to perform optimally, it requires routine maintenance. A clean and well-maintained generator carburetor is crucial to the performance of your generator. With continued use, debris and dirt accumulate and bog down a carburetor, affecting the generator’s performance. Cleaning your carburetor regularly keeps your generator running like new.

IF YOU ARE UNSURE OF ANY STEPS LISTED BELOW WE STRONGLY SUGGEST YOU CONSULT A PROFESSIONAL! ANY AND ALL QUESTIONS NEED TO BE DISCUSSED WITH A PROFESSIONAL

Why Should Carburetors Get Cleaned Regularly?

Since the carburetor is where fuel and oxygen mix to get burned, it’s akin to the generator’s heart. With continued use, dirt and debris may start building up in the carburetor. This obstructs the pipes, thus causing fuel and oxygen to detach. If your generator uses ethanol-based fuels, it’s more prone to debris buildup in the carburetor. When burned, ethanol evaporates and absorbs moisture inside the engine, thus choking the carburetor.

When a carburetor goes uncleaned, such clogs can trigger various problems, from backfiring to spluttering. Therefore, the generator’s performance will be affected significantly. Before performing maintenance on a generator, it’s best to check out the manufacturer’s website or owner’s manual for guidelines. Here, you’ll find instructions on how to clean carburetors as well as safety information. Generator maintenance instructions vary from one model to another. Thus, you shouldn’t only follow instructions that apply to your generator model when cleaning the carburetor.

How Often Should You Clean Your Carburetor?

Ideally, carburetors should get cleaned every six months to improve fuel economy, efficiency and prevent buildup. However, the frequency of cleaning carburetors varies from one model to another. The frequency with which you use a carburetor also determines how often its carburetor should get cleaned. Common tell-tale signs that you need to clean the component:

Failure to Start

If your Generac machine takes some time to start or cranks without starting, you should examine the carburetor to see whether there’s a buildup of dirt. The accumulation of grime prevents fuel and oxygen from mixing optimally and passing through to the machine. Thus, the generator will crank without starting.

The Machine Runs Lean

Generators run lean when the air-fuel balance gets thrown off. Typically, there should either be a 15:1 or 12.1 air to fuel ratio. However, if there’s more oxygen and less fuel, the intake will make popping or sneezing sounds. This often occurs when carburetors receive little fuel.

The Engine Runs Rich

If more fuel than oxygen enters the carburetor, a generator will run rich. Fuel will overrun air, thus causing black smoke to emerge from the exhaust. When this happens, the carburetor probably needs a thorough cleaning.

Grime in the Carburetor Bowl

While undertaking regular maintenance of a generator, the fuel bowl is one of the essential components to examine. It tells a lot about the carburetor's status. If there’s debris or dirt in the fuel block, the needle valve will get blocked and prevented from closing. Fuel will overflow into the carburetor and out of the fuel bowl vents, thus upsetting the oxygen to fuel ratio. The spark plugs will also get wet, thus making it difficult to start the generator.

Although the carburetor isn’t always the cause of any problem you notice, it’s usually the main culprit. To know whether it’s the carburetor causing your generator not to start, spray starter fluid into the carburetor directly. If the generator starts but doesn’t run, the carburetor needs cleaning. Knowing when to clean a carburetor will help you stay ahead of generator malfunctions.

Cleaning a Generator Carburetor

Before tackling a carburetor, make sure you have all the necessary cleaning tools. You should also clear adequate space to ensure the safety of all parts. It also makes it easier for you to clean any oil that spills when cleaning the carburetor. Some of the equipment you’ll need include:

  • A small and larger flathead screwdriver
  • 8-millimeter socket and ratchet
  • A collection of pliers
  • A cleaning rag
  • Safety goggles
  • Carburetor cleaner
  • Air cleaner
  • Two fuel line clamps


It isn’t easy to clean a generator carburetor effectively without unmounting and disassembling it. To clean a carburetor, you first need to drain it completely. Check all components and clear passageways to make sure they are free of residue. You’ll only be able to access all areas of the carburetor where dirt can build up by opening it. To clean a carburetor without unmounting it, you’ll have to use a cleaning agent meant to remove residue.

Manufacturers often recommend products that can safely get sprayed into carburetors without causing damage. These products are particularly effective if you’re getting rid of minor clogging and residue. However, if the carburetor cleaner fails to work, your best bet is to unmount the carburetor, tear it apart, and clean all areas.

Removing a Generator Carburetor

If there’s a lot of grime buildup in the carburetor, you’ll need to detach it from the engine before cleaning it. Your owner’s manual should provide in-depth guidelines on how to unmount your generator’s carburetor. Typically, you’ll have to remove the overflow hose and fuel hose besides turning off the fuel valve. The bolts that attach the carburetor to the engine also need to be removed before the throttle cable gets unhooked. Ensure you don’t misplace small pieces such as bolts, springs, and clamps.  

How to Clean the Carburetor

After unmounting a carburetor, start by checking for any signs of corrosion. With continued use, carburetors can get corroded. Continued deterioration, coupled with debris buildup, can cause the carburetor to malfunction. If a carburetor gets corroded, it makes more sense to replace it. However, if there’s no corrosion, you can clean the carburetor using the recommended solution.

Cleaning a carburetor starts with spraying the solution before allowing it to dissolve the accumulated grime. Special attention should be paid to the carburetor’s nooks and crannies because that’s where most grime accumulates. After all the grime dissolves, dry the carburetor and all its parts. The easiest way to do this is using compressed air. Blow the compressed air on all components of the carburetor and into all holes. After everything dries off, install new gaskets and O-rings into the carburetor. If the old O-rings and gaskets are still in good condition, you can reuse them.

Reassembling a Generator Carburetor

Before reassembling your carburetor, note how and where the flathead screw and bolts were removed. It will make the process easier. Start by reinstalling the main jet tube since this will allow you to slide back the main jet. The other stages of the reassembly process entail reversing the disassembly process. After the jet tube, reinstall the fuel splash plate and float needle.

Your carburetor’s outer components should be next, starting with the choke, then the idle screw, and air screw. When mounting the air screw, fasten it is all the way, then back it out one turn and a half. The idle screw only needs to be fastened in just enough to stay in place. Next, mount the float while ensuring that its holes are lined up with those of the carburetor.

After mounting the float, slide in the float pin, but ensure it’s centered so that it remains secure and able to slide around freely. To ensure that the float needle works effectively, shift the float up and down while checking that the inlet needle can move freely. In case the needle sticks in one position or doesn’t move freely, it needs to get replaced.

Remounting the Carburetor

After resembling the carburetor, proceed to remount it onto your generator. Start by installing the throttle slide onto the throttle cable. The throttle cable should be put through the carburetor’s top cap. After that, put the needle inside the carburetor’s slide, then compress the spring before hooking the cable’s end onto the slide.

Once the needle and slide are aligned, slide in the throttle slide before screwing on the carb’s top cap. The carburetor should then be slid and wiggled back into the rubber boots. Fasten the flathead screw onto the clamps to secure the carburetor into place. Once the carburetor is attached to the generator, install the overflow lines and the fuel lines before adjusting your air screw while the generator is on. You can either fasten or loosen the air screw to lean out or richen.

Slowing Grime Buildup After Cleaning a Generator Carburetor

Grime will inevitably form in your carburetor with time. However, there’s so much you can do to slow down the buildup of grime in the carburetor. It includes:

Using Fuel Stabilizers

Ethanol-based fuel accelerates grime buildup in the carburetor. They cause a buildup of carbon deposits in the carburetor, thus lowering your generator’s efficiency. Fuel stabilizers can help you avoid most carburetor problems that result from burning fuel. They get rid of the carbon deposits, hence improving engine performance and fuel efficiency. When you start using fuel stabilizers, the frequency of carburetor cleaning will reduce.

Drain the Fuel Tank Before Storing the Generator

If you only use your Generac generator at certain times of the year, it’s best to drain the carburetor before storing it. Leaving a generator idle for months with fuel encourages residing buildup, thus the need to drain it. If your generator’s carburetor doesn’t come with a drain pan and pipe, drain the fuel tank, then run the generator until it runs out of fuel.

If you anticipate using your generator at short notice, it doesn’t make sense to drain it. In this regard, consider how long the generator will be idle. Are you storing it away because you’re going on a vacation, or you’re putting it away until a power outage occurs? If the generator sits idle for longer than a month but for less than one year, fuel stabilizers will do the trick in preventing gumming.

Avoid Using Old Fuel

It’s a no-brainer that old fuel and oil can cause significant damage to engine components, including the carburetor. After draining fuel from the generator, avoid reusing it. Likewise, avoid using fuel that has been in storage for too long. Most fuels have a shelf life of 12 months. However, when stored in warm temperatures, the life span decreases significantly. Using old fuel in a generator could mean significant damage to crucial parts.

Use Cleaning Solutions Recommended for the Job

When shopping for cleaning agents for carburetors, you’ll come across tons of products. It’s tempting to grab the cheapest cleaning solution or the one recommended to you by the affiliate advertising program you signed up for. However, when dealing with parts such as the carburetor, it’s best to use manufacturer-recommended products. Some of the small engine cleaning solutions you’ll come across may work great as far as removing grime is concerned. However, they may cause erosion, especially if you fail to rinse off all the residue.

Reassemble all Parts Correctly

You may do a great cleaning job, but problems will emerge when the carburetor is put back to use if you failed to reassemble all components correctly. Strictly adhere to manufacturers’ guidelines on cleaning generator carburetors when disassembling carburetors and taking note of all connections while at it. After reassembling the carburetor and starting the generator, ascertain that there are no leaks. If you’re not well-versed in machines, it’s best to leave the carburetor cleaning job to experts rather than running the risk of ruining your generator. Alternatively, you can email the manufacturer for clearer guidelines.

Key Takeaways

Generators play a crucial role in providing backup power when outages occur. When used extensively, grime accumulates in generators’ carburetors, thus lowering their performance. One way of ensuring that a generator carburetor performs optimally is by keeping it clean and free of grime. When cleaning a carburetor, make sure you use the recommended cleaning product, besides following the manufacturer’s guidelines.