It’s tough to get your trimming job done when your string trimmer isn’t giving you the power you need. The engine won’t run at full RPMs and is bogging down.

An ECHO string trimmer has no power when old gas is restricting fuel; the carburetor is dirty; the air filter is clogged; the air filter is plugged; the spark plug is dirty; the fuel line, fuel filter, or fuel tank vent is clogged, or the spark arrestor is plugged.

Be careful working on your string trimmer. Follow all safety precautions found in the ECHO 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 prior to 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.

9 Reasons an ECHO String Trimmer Has No Power

Old Gasoline Causes an ECHO String Trimmer to Lose Power

Old gas is one of the biggest culprits to an underperforming string trimmer that loses power.

The ethanol found in most gasoline attracts moisture. This moisture and ethanol mixture leaves behind varnish and sticky deposits that cause component failure and fuel restrictions.

Because ethanol is harmful to an ECHO small engine, it’s best to purchase fresh gasoline with a minimum octane rating of 89 and a maximum ethanol content of 10%. Mix with 2-cycle engine oil at a ratio of 50:1. (50 parts gas to 1 part oil).

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 ECHO at regular intervals.

If you are unsure, add a fuel stabilizer to the gas and oil mixture so it lasts a little longer before it breaks down. Many 2-cycle engine oils contain a fuel stabilizer.

Don’t assume the stabilizer lasts longer than 30 days unless the manufacturer states it on the bottle. Some fuel stabilizers will last 30 days while others will last up to 2 years. Check out This is the Gas and Oil Fuel Mix ECHO String Trimmers Use.

SOLUTION: Drain the old fuel remaining in your string trimmer and fill it with a 50:1 fresh gas-to-oil mixture. Add a fuel stabilizer like Sea Foam Motor Treatment. This product will not only stabilize the fuel, but it will also reduce moisture and clean the fuel system.

Start the string trimmer and allow it to run to work the fresh fuel and fuel stabilizer mixture through the fuel system.

Plugged Air Filter Causes an ECHO String Trimmer to Lose Power

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 ECHO string trimmer 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 trimmer in very dusty conditions or more than the average homeowner.

You may be tempted to remove a plugged air filter that’s preventing your string trimmer 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, damaged, or wet, 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. If needed, you can wash a felt air filter in a solution of water and mild dish detergent. Rinse until the water runs clear. Allow to completely dry before reinstalling.

Some ECHO string trimmers also use a foam pre-cleaner or pre-filter with the air filter. This is added for additional protection.

To clean the foam pre-cleaner, wash it in a water and dish detergent solution and rinse. Allow to completely dry before installing. DO NOT ADD OIL to the pre-cleaner.

Consult your operator’s manual for instructions when cleaning other types of air filters.

Dirty Spark Plug Causes an ECHO String Trimmer to Lose Power

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 ECHO trimmer.

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.

Plugged Fuel Filter Causes an ECHO String Trimmer to Lose Power

In case you can’t find the ECHO fuel filter, it is located inside the fuel tank. The fuel filter should be changed out annually and more often if you use your trimmer 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.

Clogged Fuel Line Causes an ECHO String Trimmer to Lose Power

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.

Dirty Carburetor Causes an ECHO String Trimmer to Lose Power

A carburetor is required on a string trimmer 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.

Plugged Fuel Tank Vent Causes an ECHO String Trimmer to Lose Power

The ECHO 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 ECHO 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 by loosening or removing the fuel cap to allow air into the tank. Start the trimmer, and allow it to run.

Be careful and keep your string trimmer level so you don’t spill any gas from the tank. If the trimmer runs strong and doesn’t bog down and lose power, tighten the fuel cap and see if you can replicate the issue to confirm the fuel tank vent is the problem.

Solution: The fuel tank vent can be found off of a fuel line coming out of the fuel tank. If you are having problems with the vent no longer working, you must replace it with a fuel tank vent.

Plugged Spark Arrestor Causes an ECHO String Trimmer to Lose Power

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 ECHO string trimmer 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.

Carbon Buildup in the Exhaust Port Causes an ECHO String Trimmer to Lose Power

The exhaust port located behind the muffler can develop carbon deposits that can cause your ECHO string trimmer 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 trimmer, 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 ECHO String Trimmer?

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 one by visiting ECHO’s dealer locator page.

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 ECHO trimmer that’s on its last leg.

You have the weigh the reliability, quality, and age of your current string trimmer against the cost of the repair. You may be better off investing in a new ECHO string trimmer.