Chainsaw Dies When I Give It Gas: Why Is It Happening?

Have you been noticing that your chainsaw dies when you give it gas, but you don’t know why it is happening? If yes, then this is the right place for you to be.

Chainsaw dies when I give it gas is a common issue that almost every chainsaw user will have at some point. There are many reasons why this might happen, including, faults in spark plugs, faults in the carburetor, faults in the air filter, issues with adjustment screws, and more. You must thoroughly check your chainsaw to find out the cause of this issue and then resolve it as soon as possible.

In this article, you will get to know all about chainsaw dying after giving gas, why does your chainsaw start and stop, why does chainsaw dies when I give it gas, and more. Stick around to get all the answers that you are looking for.

Chainsaw dies after giving gas

Chainsaw dying after giving gas or chainsaw not starting at all is a common issue faced by many chainsaw users. It can get pretty annoying, especially when you’ve got a lot of work piled up and a mechanic isn’t available nearby.

If your chainsaw dies when you give it gas, you need to ensure that the idle screw (I) and low-speed screw (L) are adjusted correctly. You must locate the perfect setting at which the engine won’t stop once the throttle is applied. Aside from the screw setting, you need to check and make sure that the spark plug is in prime working condition. Moreover, you must also get the carburetor and fuel jets serviced properly.

Chainsaw dies when I give it gas

If your chainsaw starts properly but doesn’t stay running and stops once you give it gas, there are a few reasons why this might be happening. Some of those reasons are mentioned here – 

1. Issues with adjustment screws

The carburetor has got three adjustment screws with markings on them. They are – low-speed screw (L), high-speed screw (H), and idle screw (I). These screws will be in charge of regulating the fuel flow to the carburetor.

For instance, the L screw will control the gasoline entering the carburetor at low/idle RPMs, while the H screw will regulate the fuel flow at higher RPMs. The I screw will be a butterfly valve that controls idle RPMs by lowering or raising the flow of the air-fuel mixture.

When the screw is tightened, the fuel flow to the carburetor will be restricted, which causes the mixture to be lean. This will cause the engine’s RPMs to increase the set limit before it starts decreasing. On the other hand, loosening the screw will enrich the mixture with gasoline and lower the RPM to the set limit. When the L or I screws aren’t set properly, the idle RPMs fall too low, and the engine stalls or stops working once you give it gas.

2. Fault in the fuel flow system

Your chainsaw’s fuel supply system will comprise the gasoline tank, fuel lines, fuel filter, and carburetor. Any obstruction in any of these components might disrupt the fuel flow to the engine, which will lead to the engine bogging down while idling. The usage of stale ethanol-blended fuel, which results in sticky white deposits over time, will be the most typical source of such clogs.

These deposits end up accumulating at the fuel filter or carburetor jets, ultimately blocking them and impeding the fuel flow. In such situations, vapor locks created in the fuel tank because of insufficient venting could cause engine issues. All fuel supply components should be examined independently to address such difficulties.

3. Ignition and exhaust problems

The ignition system will include the spark plugs, exhaust muffler, and ignition coil. The spark quality of the spark plugs tends to degrade over time, which makes it impossible to ignite the air-fuel mixture in the combustion chamber.

Further, the arrestor screen that catches the spark of the exhaust port is quite prone to carbon deposits. These deposits will affect the engine’s operation and might cause the chainsaw to stop when you give it gas.

4. Issue with the spark plugs

 The biggest culprit could be the spark plug and filters.

With the spark plug, you must remove the plug from your chainsaw, and you might find that the spark plug is quite dark and covered in carbon. First, you need to try and clean the plugs with a wire brush gently. Make sure that you are careful and don’t damage the enamel insulator around the electrodes. 

There might be an issue with the gap in the spark plug. In case it is out of line, the spark plug will not work. There is a special tool that can be used to check and adjust the gap. If cleaning the spark plug doesn’t work, you might have to consider replacing the spark plug.

5. Issues with the filters

The next thing that you should check will be the filters. The purpose of one of the filters is to make sure that debris doesn’t get into the fuel, while other filters help in regulating the air circulation. If air circulation gets compromised, the engine will not function properly and efficiently. The air coming into the engine through the intake port could get hampered by a dirty filter, which could disrupt the airflow and stop the engine.

To resolve the problems with filters, you need to replace the fuel filter, which is normally found in the gas tank. It can either be repaired or removed and replaced quickly. You must also change the air filter while checking the spark arrester. They can be found beneath the cover on the engine housing and, similar to the fuel filter, they can be removed easily and serviced.

6. Issues with the fuel

Issues with fuel can easily arrive when the chainsaw has been sitting idle for a long time. If the chainsaw has been in storage for a while, the gas left in the carburetor and fuel lines might have started evaporating. This will leave behind a sort of varnish, which can clog up the system.

Another issue could arise if the fuel has had the presence of moisture in it. When the moisture mixes with ethanol in the fuel, it could settle at the bottom of the fuel where the fuel line is supposed to be. It has the same effect as the varnish in that it’ll clog the fuel system.

The solution will be to remove the old fuel, remove the fuel lines, and then spray them with a carburetor cleaner. This will help in dissolving the deposits.

7. Carburetor issues

Another reason your chainsaw stops when you give it gas could be the carburetor. When you’re replacing the spark plugs, you might have found them to be coated in black carbon deposits.

This might be a sign that the fuel mixture is too rich. If that happens, you will need to adjust the carburetor. You must check your owner’s manual to do this. With most chainsaws, the amount of fuel distributed by the carb into the combustion chamber can be easily regulated by turning an adjustment screw.

If the engine dies when you press the throttle, you’ll have to tighten the speed adjustment screw. Your manual will instruct you on how to do that.

How to Diagnose a Chainsaw That Starts and Stops, or Bogs Down | eReplacementParts.com

How to repair a chainsaw that dies when you give it gas

1. Adjusting the throttle screw

As mentioned above, the carburetor comprises three screws (H, I, L) for managing the entire RPMs at high, idle, and low speeds. If the chainsaw continues stalling, the issue might be with the low-speed and idle screws, which you will need to adjust.

Screw adjustment at low speed

For carrying out the low-speed screw adjustment, you will need to follow these steps –

• Turn on the engine – Start the chainsaw and then tighten the chain. You must give it a few seconds of idle time. Moreover, keep track of whether the engine idles smoothly or if it dies.
• Tighten the screw – If the engine dies while you’re idling, tighten the screw using a screwdriver for increasing the idle RPM. As you tighten the screw further, the RPMs will start falling. Remember to make note of the location of this point. Loosen the screw further, which allows the RPMs to increase until they start declining. Remember to make a mental note of this point’s location, too.
• Locate the ideal spot – The ideal screw setting would be somewhere in the middle of the two settings. Turn the screw until the perfect balance has been achieved, and then stop. At this time, the idle RPMs will be adequate to keep the engine going. Further, the engine will respond significantly quicker and without delay once the trigger is pulled.

Get the idle setting

The chain might start rotating as the mixture is lean enough to engage the clutch after you’ve done the low-speed adjustment. If the chain starts spinning, you will need to loosen the idler screw until it stops. It is crucial as an idle chain is very harmful. If the chain doesn’t rotate, you should skip this step.

Following the L modification, the mixture composition needs to be adequate in keeping the engine running. Sometimes, the L adjustment could be sufficient, and you’ll have to tweak the fuel delivery components, specifically the filers and the carburetors.

2. Examining the fuel system

The carburetor should be maintained properly, but first, you’ll have to check that the engine’s filters are spotless.

Air filter

Using a screwdriver, you should remove the air filter cover on the back of the chainsaw. Now, you should remove the filter and clean the dust buildup with a brush. Cleaning it by immersing it with a soap-water solution will be preferable. If you notice any signs of damage or wear on the air filter, it is recommended that you replace it.

Fuel filter

You will find the gasoline filter at the bottom of the fuel tank. Drain the fuel tank and then store the gasoline in a container before bringing it out. Now, remove the filter from the tank’s bottom before cleaning the gasoline deposits from the filter’s jets with a metal wire. After you’ve cleaned, attached it back to the gas tank.

Carburetor

Remember to get a carburetor repair kit before you start clearing the blocked jets. A carb cleaner spray will be a great tool for eliminating sticky deposits from the jets and reviving the carburetor.

• Step 1: Remove the air filter – You will need to remove the air filter to start cleaning the carburetor. Often, the air filter is found at the rear of the chainsaw.
• Step 2: Remove and clean the bowl – Now, you must take the bowl and then bowl out of the carburetor. Old gasoline and its impurities can be typically found in the bowl. Any remains or old fuel needs to be removed thoroughly.
• Step 3: Make use of a carb cleaner – Now, sprinkle a bit of carb-cleaner liquid in the carburetor and its components.  Remember to always clean the bowl nut, a jet that’s likely to be clogged. When the spray exits from the other end of the jet, it’ll mean that any debris that was stuck will be cleared.

3. Examine the spark plug properly

Finally, if all the previous methods fail to resolve the issue, you can fix the spark plug. The ignition system is basically a spark plug. Even if you’re a beginner chainsaw user, the spark plugs need to be updated at least once per year.

Due to continuous firing, the spark plug’s electrodes will get damaged or acquire carbon deposits, reducing the spark quality. If this is the case, the only alternative would be to replace the spark plug.

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