When the engine isn’t giving you good power, you’re not getting good performance out of your edger.
An edger bogs down and loses power due to a dirty carburetor, clogged air filter, plugged fuel filter, dirty spark plug, clogged fuel line, plugged fuel tank vent, plugged spark arrestor, or bad fuel.
Follow all safety precautions found in your operator’s manual. This includes removing the spark plug wire and waiting for the engine to cool before performing repairs.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
An Edger Bogs Down and Loses Power (9 Things to Check)
1. Old Gasoline
Over time gasoline can break down and cause running problems in an edger. Using old fuel can cause fuel restrictions and damage to the carburetor and engine.
The ethanol found in most gasoline attracts moisture. This moisture and ethanol mixture leaves behind varnish and sticky deposits.
Because ethanol is harmful to a small engine, it’s best to purchase fresh gasoline with a minimum octane rating of 89 and a maximum ethanol content of 10%.
2 cycle engines require gas to be mixed with premium 2-cycle engine oil. 4-cycle engines require straight gas. An exception to this is STIHL’s 4-MIX engines which require a gas and oil mixture.
Tips for purchasing and storing fuel for an edger:
- Never use fuels with higher ethanol contents like fuels sold as E15, E30, and E85 fuel. These have ethanol contents up to 15%, 30%, and 85% respectively.
- Consume fuel within 30 days. It can be difficult to estimate how much fuel you will go through especially if you don’t use your edger at regular intervals.
- Add a fuel stabilizer to the gas and oil mixture so it lasts a little longer before it breaks down.
SOLUTION: Drain the old fuel remaining in your edger. Mix fresh gas with a fuel stabilizer like Sea Foam Motor Treatment or STA-BIL
This product will not only stabilize the fuel, but it will also reduce moisture and clean the fuel system.
Start the edger and allow it to run to work the fresh fuel and fuel stabilizer mixture through the fuel system.
2. Plugged Air Filter
An air filter allows the engine to get clean air while keeping dirt out. When the filter isn’t cleaned or replaced regularly, it can become plugged restricting the amount of air allowed to pass through the filter.
Without sufficient air, an edger will run sluggishly and lose power.
I recommend replacing the air filter once a year and cleaning it several times throughout the year. You will have to clean and replace it more often if you use your edger in very dusty conditions or more than the average homeowner.
You may be tempted to remove a plugged air filter that’s preventing your edger from running strong. Do not do this even if it’s only for a few minutes to finish a task.
Doing so can contaminate the engine with dirt and debris causing permanent engine wear and damage.
SOLUTION: Remove the air filter cover and the air filter. Wipe out any dirt remaining in the housing and cover. Inspect the filter. If it is excessively dirty or damaged, replace it with a new air filter.
If it appears to be in good condition and a little dirty, brush the dirt from the filter and reinstall it.
Clean an edger FELT/FABRIC air filter:
- Remove the air filter cover and air filter.
- Clean the felt air filter using water and mild detergent.
- Rinse the filter until the water runs clear and allow it to air dry.
- Allow it to air dry completely.
- Reinstall the filter.
- Reattach the air filter cover.
Consult your operator’s manual for instructions when cleaning other types of air filters.
3. Dirty Spark Plug
A spark plug that is dirty can cause intermittent spark resulting in a loss of power. Remove the spark plug and check its condition.
SOLUTION: If it is very dark in color or is damaged, it needs to be replaced with a new spark plug.
You can try cleaning a lightly dirty plug using a small wire brush. I prefer to replace the plug since it is a vital component of a well-running edger.
Next, check the electrode gap. This must be gapped to the manufacturer’s specification. The spark plug wire must be securely attached as well. A loose spark plug wire or an incorrect gap can cause a loss of power.
4. Plugged Fuel Filter
In case you can’t find the fuel filter, it is located inside the fuel tank. The fuel filter should be changed out annually and more often if you use your edger more than the average homeowner or if you find it is worn or damaged.
The fuel filter stains fuel as it comes out of the fuel tank. It is used to prevent dirt and other contaminants from entering the fuel system.
A filter can become clogged and prevent a good flow of fuel to the engine resulting in a loss of power.
SOLUTION: Replace a fuel filter that isn’t allowing fuel to pass through to the fuel line.
Check the fuel tank to make sure the fuel is of good quality and it’s not contaminated with dirt and debris. If the fuel is very dirty or old, replace it with fresh clean fuel.
5. Clogged Fuel Line
The fuel line can become restricted with gummy deposits left behind from using old fuel. These can prevent a good flow of fuel to the engine resulting in power loss.
SOLUTION: Inspect the fuel line looking for any clogs preventing fuel flow. Replace a fuel line that is clogged, kinked, or has developed cracks from age.
6. Dirty Carburetor
A carburetor is required to regulate the amount of gas mixed with air to create combustion. Old fuel can gum up and cause the small components in your carburetor to stick so it no longer functions right.
SOLUTION: If you are a little mechanical you should be able to handle cleaning your carburetor. Clean the carburetor by taking it apart and using carburetor cleaner to clean it.
If the carburetor does not function after being cleaned, you may need to rebuild it (if a rebuild kit is available) or replace it with a new carburetor.
7. Plugged Fuel Tank Vent
The fuel tank vent can become plugged preventing air from passing through the vent to equalize the air pressure in the fuel tank.
A plugged vent can cause a vacuum to form in the fuel tank keeping fuel from flowing out of your fuel tank.
If fuel isn’t running through the fuel lines and you don’t have a clogged line or a plugged fuel filter, there is a good chance the fuel tank vent is plugged.
You can test this using a pressure gauge to find a vacuum problem. If you don’t have a gauge, try this:
- Start the engine and allow the edger to run.
- Place the edger on a level surface.
- Loosen the fuel cap to allow air into the tank. Don’t allow fuel to spill out of the tank.
- If the vent is causing your edger to lose power, the engine will begin to run better with the cap loosened.
- Confirm the vent is the problem by securing the cap and using the edger to see if you begin to experience a power loss.
SOLUTION: The fuel tank vent can be found off of a line coming out of the fuel tank or built into the fuel tank cap. If you are having problems with the vent no longer working, it’s time to replace it.
8. Plugged Spark Arrestor
The spark arrestor is a small metal screen that prevents hot exhaust material from leaving the muffler and starting a fire.
When this small screen becomes plugged you may experience a loss of power where your edger won’t run at full RPMs.
SOLUTION: Disconnect the spark plug wire. Remove the engine cover and the engine exhaust cover. Carefully remove the spark arrestor screen. Clean it with a metal brush.
If the screen isn’t able to be sufficiently cleaned or you find it is damaged or has a hole in it, replace it with a new spark arrestor screen.
9. Carbon Buildup in the Exhaust Port
The exhaust port located behind the muffler can develop carbon deposits that can cause your edger running problem.
This area should be checked and cleaned when you are experiencing a loss of power that hasn’t been fixed by the items above.
SOLUTION: To avoid damage to the edger, I recommend having an experienced mechanic clean the exhaust port and muffler.
If you choose to attempt to clean it, first disconnect the spark plug wire and make sure the engine and muffler are cool so you don’t burn yourself.
Remove the engine cover, the muffler, and the heat shield. Adjust the piston until it covers the port opening. This will keep carbon from falling into the cylinder.
Use a plastic scraper to remove the carbon buildup around the exhaust port. DO NOT use a metal tool. Do not scratch the piston or the cylinder during this process.
Reinstall the items in the reverse order you removed them.
When to Have a Mechanic Repair Your Edger
If you’ve gone through the list above and it didn’t solve your loss of power issue or you don’t feel comfortable performing any of the repairs, it is time to consider consulting an experienced small engine mechanic.
You may have a good small engine repair shop near you that has been recommended by a neighbor or friend. You can also find a servicing dealer for your model edger in the area.
Check out these links for dealers in your area:
I prefer to go to the dealership for manufacturer-trained support when I run into a significant issue. They have the proper equipment to perform necessary testing.
They also carry OEM parts and can take care of any warranty items.
When visiting the repair shop, keep in mind the labor rate for the mechanic to diagnose your problem. There is typically a flat rate charge to diagnose the problem and then add labor and parts fees in addition to the fee to make the repairs.
Paying a diagnostic fee, parts, and a labor bill may not be sensible if you are running an old inexpensive edger that’s on its last leg.
You have the weigh the reliability, quality, and age of your current edger against the cost of the repair. You may be better off investing in buying a new edger.