How To Fix A Chainsaw That Starts Then Dies When You Give It Gas
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Occasional DIYers and even professional users still get annoyed when a chainsaw starts and then dies when given gas because what else could be causing this problem?
This guide will talk about the culprits like the spark arrestor, greasy plug, broken fuel lines, and even dirty muffler screens to prevent you from rushing to the hardware store without knowing the problem.
Why Does My Chainsaw Die When I Give It Gas?
1. Fuel Supply Issues
Stubborn deposits are one of the most common reasons why your chainsaw continues to stall. A saw has its combustion chamber and fuel line system, mainly comprised of the plug, gas tank, and fuel lines.
Unruly debris or deposits can cause these parts to become clogged. Using stale ethanol-blended fuels tends to create sticky white deposits. These can cause clogs that lock the vapors inside the tank, and prompt engine bogging.
2. Problems With Ignition
Spark plugs can fail, especially if they have been used for a while. They are usually covered with black carbon deposits from too-rich fuel mixtures.
Spark arrestor screens and exhaust ports can become clogged with deposits. This will lead to ignition problems, which can cause your chainsaw to stop working.
3. High-Speed, Low-Speed, And Idle Screws
The engine can also stall if there is a problem with the tension of these three screws. The three adjustment screws that make up a chainsaw carburetor are the low-speed (L), idle (I) and high-speed (H).
These screws have different functions, and when one is tightened or not set properly, it can restrict fuel flow or cause RPMs to fall too low, prompting the engine to stop even with gasoline.
How To Fix A Chainsaw That Won’t Start Properly After Filling It With Gas
1. Check Your Filters
Before you start with the carburetor it is important to inspect the filters. Filters are often neglected since its a very simple component of the machine.
But dirty filters are a common culprit to saw problems. Before cleaning, make sure to locate and remove the spark arrestors located behind the muffler.
Air Filter
To remove the cover from the back of the saw, use a screwdriver. Check for any debris that could clog your fuel system and airway.
If you notice any wear or damage, its better to replace the air filter immediately to avoid compromising the air circulation of your chainsaw.
Fuel Filter
Locate the fuel filter at the bottom of the fuel tank. Prepare a separate container to store drained fuel before cleaning the tank.
Use a metal wire to brush stale gasoline deposits. Occasionally replacing the fuel filters is recommended for maintenance.
2. Examine The Carburetor
The carburetor of a chainsaw is delicate and should be inspected carefully. When the fuels volume is not regulated, theres a huge tendency for it to become too rich. This is when you will need to adjust your carburetor.
Clean the carburetor
- Remove the air filter. Remove the cover from your chainsaw’s rear end to clean it.
- The bowl and nut should be removed from the carburetor. You can remove any fuel remaining in the bowl by wiping it clean and cleaning out any impurities.
- Sprinkle a carburetor cleaner. Spray a carb cleaner liquid inside the carburetor and outwards to clean it thoroughly. This will prevent the jet from jamming. Spray the other side to check if it is clear. If it passes through, you have cleared all stuck debris.
Adjustments to the screws
To avoid any problems in the combustion chamber, it is important to adjust your carburetor. Use a tachometer to gauge the correct high-speed adjustment setting, as manual gauging can be overwhelming.
Rebuilding or replacement
If your carburetor has been cleaned but it still dies, the damage is already done. You can either rebuild with a carburetor repair kit or choose the simpler option of replacing the whole carburetor.
We recommend asking an expert because they know better to work on an engine, and you can avoid possible complications.
Fix #3: Inspect The Spark Plug
Spark plugs should be inspected every once a year to avoid ignition problems for sparking up. Check for any gaps that could be the culprit to ignition and fuel issues. Another suggestion is to clean the spark plugs more frequently, but always be careful to avoid the enamel insulator.
Clean the spark plug
Use a wire brush to clean the spark plug, and remove any excess deposits. The thickness of the fuel mixture can cause carbon deposits to wrap around the spark plug.
Replacing
Continuously firing your chainsaw can cause the spark plugs electrode to experience huge damage, resulting in a degradation in the quality. When this happens, its best to get a new spark plug instead.
Fix #4: Adjusting The Screws
The chainsaw’s performance will be improved if the screws are properly gripped before you press the throttle. It is also important to make adjustments from time to time. If the throttle is not bogging the engine, depress it and tighten the low- or high-speed.
Low-speed
To control how much gasoline deposits get into the combustion chamber at low speed, adjust the L screw. To ensure the correct hold, you must properly gauge and tighten it.
High-speed
To avoid any serious damage to your carburetor, make sure that the High-Speed Screw stays closed. The combustion chamber can become clogged with air, preventing ignition. Adjust the L setting until it is sufficient to keep your engine running.
Idle
The chain will start spinning when the fuel mixture is too engaged with the clutch. Adjust the idler screw to prevent this from happening. You should take extra precautions with this step as they can be dangerous butterfly valves.
Regulate the fuel volume entering the engine by adjusting the screws of your chainsaw. Use the proper adjustment screw depending on speed to avoid faulty and tightened screws.
Other Possible Causes
Vapor Lock
Another possible occurrence is fuel vapors building pressure which causes vapor lock. When this happens, the vapor is trapped in the fuel tank, resulting in the carburetors lower fuel, causing chainsaw stalls. Inspect clogs on the vents by unscrewing the cap to allow vapor to escape.
Air Leak
Air circulation can cause engine problems if it is not checked. Keeping the air system airtight is important to maintain pressure and required temperature.
Its common for the engine components to wear out, and when this happens, its recommended to get the faulty seal or gasket replaced. Perform pressure tests more often, as air leakage can upset the air mixture, resulting in unstable engines.
Conclusion
When a chainsaw starts then dies when you give it gas, fixing it can be a little challenging, especially if you think youve already mastered your saw.
It is an inconvenience woodworkers often face. Therefore, it is important to replace the fuel filter in order to prevent a faulty fuel flow.
