Chainsaw Cuts Out When Throttle is Applied: Expert Tips

Are you frustrated with your chainsaw cutting out every time you apply the throttle? We understand how this can hinder your progress. Our expert advice is here to help you resolve this issue and get back to your work.

The chainsaw cuts out when the throttle is applied; what to do:

A chainsaw stalling at full throttle is often due to a clogged fuel filter, air filter, carburetor, or carbon buildup. Inspect the fuel system, clean air filter, and carburetor. Remove the spark arrestor screen to clean. Regular maintenance prevents buildup, restricting airflow/fuel.

Is a faulty chainsaw slowing down your progress? We have expert tips to help you troubleshoot and get back to work. Learn about the common causes and how to address them. Continue for more expert advice!

Causes and Fixes of a Stalling Chainsaw at Full Throttle:

There may be one of these various reasons that are causing your saw to stall at wide-open throttle (WOT). It would be best to begin the troubleshooting by investigating these causes individually.

● 1. Clogged Fuel Filter:

Fuel filters are situated at the inlet of the fuel line that carries the gasoline from the tank to the carburetor. Deposits accumulate on the gasoline filter located within the fuel tank due to poor gasoline quality.

As the name implies, it filters the fuel so the carburetor receives a clean and uncontaminated gasoline charge. However, when it becomes blocked, the fuel flow to the engine is disrupted, causing the engine to stall.

– Expert Opinion:

Based on my experience working at multiple chainsaw forums and addressing various chainsaw-related issues, I recommend you begin the inspection from the fuel filter first, as it is the leading cause of a stalling engine.

Besides getting clogged, the filter might also come off the fuel line. As a result, the carburetor will not draw enough gas when there is a high demand for gasoline at WOT, causing the engine to stall.

Hence, you need to open the fuel tank and see if the filter isn’t lying there while being dislodged from the fuel line.

– Repair: Fuel Filter Inspection and Replacement:

Remove the chainsaw’s fuel cap to inspect the fuel filter and pour gasoline into a different container. Then, using a dental pick or a thin metal rod, filter the tank.

Examine the filter’s quality. If It appears clogged, you should buy a new filter and replace the old one. If it seems clean, leave it as it is and consider checking the fuel lines, carburetor, and air filter for restrictions.

● 2. Fuel Lines:

Any slight restriction or debris in the fuel lines can suffocate the engine from gasoline at peak demand for fuel, thus causing it to stall. The fuel line might get clogged due to stale fuel deposits. Or it might have become cracked.

– Expert Opinion:

When the fuel line has become cracked, it leaks gasoline and draws air from outside into the fuel line. At WOT, a vacuum is formed in the fuel lines, inhibiting the gasoline flow to the engine. Therefore, the fuel lines need to be tight at their connections to eliminate any chances of vacuum formation.

– Repair: Inspect the Fuel Lines:

If the line leaks fuel, you should know that replacing it is the only way. However, if you see that the stall persists after you’ve troubleshot other methods, try examining your line at its connection to the tank and see if it’s tight enough in case it is inhibiting the gasoline flow.

● 3. Dusty Air Filter:

You should examine the air filter before checking the carburetor, as it is easier. As a fuel filter, an air filter filters out the dust contaminants present in the air before going into the carburetor.

However, when the filter gets plugged with dirt and dust, it filters too much air, thus depriving the engine of adequate air necessary for combustion. Hence, the engine is likely to stall.

– Expert Opinion:

A dusty air filter might be the most common issue when the engine is generally stalling and not at WOT. If the filter had been clogged, your engine would not start at first, or if it does start, it will continue to stall even at lower RPMs.

Our problem is the engine stall at higher RPMS (or WOT), the most common causes of which include the fuel filter and carburetor.

Nevertheless, cleaning the air filter has solved the issue for most individuals, and that’s why you should consider doing so, as it’s not a difficult task, and cleaning it ensures that the engine runs smoothly.

– Fix: Cleaning the Air Filter:

Your chainsaw’s air filter screen is located at the rear. First, loosen the fasteners with a screwdriver that holds the air filter in place. Next, remove the filter and inspect it for dirt/deposits. A soap and water solution shall suffice if the dirt buildup isn’t too significant.

However, consider replacing it entirely if it does not appear in good condition after cleaning. Air filters are relatively inexpensive, and you should replace them once a year to reduce engine problems.

● 4. Clogged Carburetor:

If fixing the filters hasn’t solved the problem, you’re probably looking at a clogged carburetor. A carburetor mixes the air and gasoline and supplies the mixture to the engine for combustion. Unfortunately, fuel stored in the tank for longer durations is bound to degrade in quality.

As a result, it forms white, sticky deposits that clog the fuel jets of a carburetor and ultimately affect the amount of fuel going to the engine. Hence, the carburetor needs to be serviced to ensure its normal functioning.

– Expert Opinion:

To confirm that the engine stall at WOT is due to a carburetor, I advise bypassing the current fuel line and creating an alternative line that pumps fuel from a separate bottle into the carburetor. The carburetor must be appropriately checked and serviced if the engine still stalls at WOT.

Also, during this operation, most users experience bubbles forming in the WOT fuel line. These bubbles further confirm that the engine cannot draw sufficient fuel at peak demand, and thus, it stalls. The stall should subside as soon as the throttle is lowered.

To ensure that you remain on the right track, pay special attention to the needle while cleaning the carburetor, as this is responsible for drawing fuel from the fuel lines. If the needle gets stuck, the carburetor won’t remove enough fuel.

– Fix: Carburetor Cleaning:

Because small engines, such as those found in chainsaws, have fewer mechanical parts, carburetor cleaning is significantly easier. You only need a standard carburetor cleaning spray. The following are the steps:

Step 1: Identify the carburetor:

To begin, find the carburetor of your chainsaw. It is usually located behind the air filter. So, if you removed the air filter before, you should have easy access to the carburetor.

Depending on your ability level when performing DIY work, you can consider removing and cleaning it or cleaning it without completely detaching it from the chainsaw. Nonetheless, we do not recommend thoroughly disconnecting it as it complicates the job.

Step 2: Detach and clean the bowl:

First, remove the bowl nut from the carburetor and remove the bowl. Most of the time, the bowl contains expired gasoline and its deposits. As a result, it should be cleansed of any residues and old gasoline.

Step 3: Spray the carb cleaner on the interior:

Next, spray some carburetor cleaner liquid over the carburetor’s inner portions. Don’t forget to clean the bowl nut, which is a jet and is more prone to becoming clogged.

When you observe spray pouring out of the other side of a jet, it means that any debris has been removed. After you’ve finished cleaning, reassemble everything that was removed.

● 5. Clogged Muffler:

If the engine stall persists after you’ve troubleshot each of the above components, the muffler is another component that contributes to this problem occasionally.

The muffler contains the spark arrestor screen and the exhaust port. The carbon buildup from the fuel can often clog the spark arrestor screen or the exhaust port. It might be another reason behind the engine shutting down at full throttle.

– Expert Opinion:

Most users ignore the muffler and the spark arrestor while encountering such a problem. If you delve deep, excessive carbon buildup occurs at the exhaust, mainly when your engine runs rich.

(Primarily, this is when you run the engine at full throttle; at higher RPMs, the air-fuel mixture becomes rich or high in gasoline). Richer mixtures produce a higher value of carbon content at the exhaust.

It means that carbon deposition is maximized at WOT. Hence, this is precisely why the exhaust gases cannot escape at full throttle, causing the chainsaw to cut out.

– Repair: Clean the exhaust port and spark arrestor screen:

To clean the spark arrestor screen, remove it and use a propane torch (if available) to dislodge any carbon deposits. Instead of a torch, you can also use a wire brush to clean the arrestor screen.

Also, use the same wire brush to see if the exhaust port can be cleaned from the soot deposits. After cleaning, fix everything back and check if the problem is solved.

Remarks

To summarize, engine stall or shutdown-related problems arise from fuel supply or ignition system hitches. This can be particularly noticeable when your chainsaw is running. Issues such as a fuel line blockage or a carburetor can cause this symptom.

Hence, you minimize such occurrences through occasional maintenance such as regular cleaning, servicing components, and fresh fuel addition. It’s essential to understand how a carburetor can cause this. When mixing fuel and air, if the mixture is not correct, it can lead to problems.

• Fuel Consumption and Chainsaw Power

The more fuel it will burn, the more power your chainsaw will have. However, mixing issues can lead to problems. If you notice while dismantling your carburetor for rebuilding that it is corrupted internally, you should replace it.

Also, start with the air filter. If it is damaged, it can affect the performance of your chainsaw. This article informs you of the basic troubleshooting steps needed if you encounter a problem with your chainsaw.

It is an excellent practice to try to fix your tools independently. If, however, the problem persists, consider consulting a professional. For more detailed information, please see our carburetor section. Remember, if you tear it, you can fix it. But always be careful when dealing with components like the carb itself.