Nothing completes the manicured look of your lawn like a string trimmer. You rely on it to trim grass around your fence posts, water features, and landscaping. When it starts acting up and not starting, it’s time to fix it so you can continue to enjoy your lawn’s pristine appearance.

An ECHO string trimmer will not start when the engine isn’t getting sufficient air, fuel, and spark. This can be due to a plugged air filter or fuel filter; a clogged fuel line; a dirty carburetor; a bad spark plug; a plugged spark arrestor; or an incorrect fuel mix.

Before performing any repairs, wait for the engine to cool if it has been running previously. Remove the spark plug and follow the safety precautions outlined in your ECHO operator’s manual.

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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.

Start with Checking & Replacing Your ECHO Maintenance Parts

When you find your ECHO string trimmer won’t start, the best thing to do is to first rule out the air filter, fuel filter, and spark plug as being part of the problem.

These are the maintenance items that should be replaced annually or more frequently to help keep your trimmer running at its best. ECHO sells maintenance or tune-up kits that include the air filter, fuel filter, and spark plug.

Reasons Your ECHO String Trimmer Will Not Start

Plugged Air Filter Will Cause an ECHO String Trimmer to Not Start

The air filter is an essential part designed to keep dirt from entering the air intake and causing wear on the engine. The air filter can become plugged when it isn’t regularly cleaned or replaced.

A plugged air filter will restrict airflow. Your ECHO string trimmer won’t start when it doesn’t get enough air.

Replace an ECHO air filter annually and check it after every 10 hours of operation to make sure it is still in good condition. Check it more frequently in dry dusty conditions.

If you find the filter is damaged, very dirty, or wet, you must replace it. If it’s just a little dirty, remove the filter and clean it by brushing dirt off the filter.

NEVER run your ECHO string trimmer with a very dirty air filter or without an air filter. It can be tempting to try to finish your trimming task by removing a plugged filter and running the trimmer while you wait on a new filter replacement.

If I were you, I wouldn’t risk it. This can allow dirt to enter the engine and cause permanent damage.

Solution: Remove the filter and wipe out any remaining dirt from the air filter housing and cover. Replace a dirty air filter with a new ECHO air filter.

Bad Spark Plug Will Cause an ECHO String Trimmer Not to Start

The spark plug is another maintenance item that should be replaced once a year to keep your ECHO string trimmer running at its best. Over time, the spark plug can become dirty causing it to misfire or have intermittent starting problems.

A loose spark plug wire or incorrectly gapped string trimmer can cause a string trimmer to fail to start as well.

Solution: Before removing the spark plug, wipe around the plug to remove all dirt and debris. Remove the plug and check its condition. Replace a spark plug that is very dark in color, has signs of wearing or is damaged.

You can attempt to clean a mildly dirty spark plug with a wire brush and reuse it. I prefer to replace it. It is an inexpensive part and one of the primary items responsible for keeping your ECHO string trimmer running.

Make sure your spark plug is gapped to the manufacturer’s specification, install the spark plug and securely attach the spark plug wire (boot).

Plugged Fuel Filter Will Cause an ECHO String Trimmer Not to Start

The fuel filter used on an ECHO string trimmer can be found in the fuel tank. This filter is used to strain fuel before it enters the fuel pick-up tube. It is designed to keep dirt and debris out of the fuel system.

Just like the air filter, the fuel filter can become plugged when it isn’t changed out regularly. I recommend replacing the fuel filter at least once a year while checking it periodically.

If you find your fuel is dirty, you may need to drain the fuel tank, fill it with fresh fuel and replace the fuel filter.

When the fuel filter becomes clogged with dirt, it will restrict the amount of fuel that is able to flow through the filter and into the fuel lines. This can keep your ECHO’s engine from getting the fuel it requires to start and run.

Solution: Locate the fuel filter inside the fuel tank and replace the plugged filter. Replace the fuel if you find it dirty as well.

• Wipe around the fuel cap to remove any loose dirt so it doesn’t fall into the fuel tank once you remove the cap.
• Gain access to the filter. A clean bent wire works well to “fish” the filter and pull it out of the tank.
• Remove the old filter from the fuel line. Be careful not to lose the retaining ring securing the line to the filter.
• Install the new fuel filter securing the fuel line to the filter using the retaining ring.
• Place the filter back inside the fuel tank and reinstall the fuel cap.

Incorrect 2-Cycle Oil Mix in an ECHO String Trimmer Will Causing Starting Problems

Using straight gas or the wrong ratio of gas to oil mix can damage the engine and cause it to seize up. Straight gas added to your ECHO string trimmer is a quick way to damage the engine.

Read more information in “This is the Type of Gas and Oil ECHO String Trimmers Use”.

ECHO 2-Cycle Gas to Oil Mix

A 2-cycle ECHO string trimmer requires a gas-to-oil ratio of 50:1. 50 parts gas needs to be mixed with 1 part oil.

When creating the oil and gas mixture, use unleaded gasoline with a minimum octane rating of 89 (mid-grade) and maximum ethanol content of 10%. Add a 2-cycle premium oil that is ISO-L-EGD and JASO M345 FD certified.

Mix it in an approved gas can before adding it to your string trimmer. ECHO recommends using an ECHO 2-cycle oil like ECHO Power Blend or ECHO Red Armor.

2-Cycle ECHO Premixed Fuel

A great option to reduce fuel problems and extend engine life is using an ethanol-free fuel mix. This is an ethanol-free blend of oil and fuel that is ready to pour into your string trimmer’s fuel tank.

You won’t have to deal with the bad effects of ethanol as discussed in the fuel section. Also, it’s convenient to have fuel available on your shelf when you need it. ECHO Red Armor Premixed and TruFuel are good 50:1 premixed fuel options.

Solution: Drain the fuel tank and fill it with the correct gas to oil mix. If you continue to have problems, have a small engine mechanic diagnose the problem and determine whether a cost-effective repair can be made.

Old Fuel in an ECHO String Trimmer Will Cause Starting Problems

Old fuel left in an ECHO string trimmer won’t only cause fuel restrictions, but it can also damage the carburetor and engine.

Because ethanol is found in most types of gasoline and gas begins to break down as soon as 30 days after purchase, it’s important to use fresh gasoline with low ethanol content.

Ethanol is not kind to the small engine used on your ECHO trimmer. This product naturally attracts moisture from the air causing premature corrosion and fuel restrictions.

The ethanol and water mixture not only leaves behind varnish and gummy deposits, but it can also separate from gas over time causing potential engine damage.

Because of this, always use unleaded gasoline with a minimum octane rating of 89 (mid-grade) and maximum ethanol content of 10% (E10). Never use E15 or E85 in the engine as this will damage the engine and most likely void manufacturer warranties.

I know it’s hard to know how quickly you’re going to go through fuel. It’s like trying to anticipate how much rain and sunshine you’ll see that will impact how quickly the grass grows.

To keep your fuel system clean and to reduce the negative effects of ethanol, add a fuel stabilizer.

I like Sea Foam Motor Treatment as a fuel stabilizer. Some 2-cycle oils include a fuel stabilizer, but you’ll need to read the details on the oil bottle to determine how long the product will stabilize the fuel.

For example, ECHO Power Blend includes a stabilizer, but it’s good for 30 days. ECHO Red Armor states it’s good for up to 2 years. Don’t assume that just because the oil you use states it includes a fuel stabilizer that it will stabilize the fuel for longer than 30 days.

Solution: Drain any old fuel remaining in your string trimmer and fill it with fresh fuel. This is an oil and fuel mixture for the 2-cycle engine on your ECHO trimmer.

Bad Primer Bulb in an ECHO String Trimmer Will Cause Starting Problem

A cracked ECHO primer bulb that won’t fill up with fuel won’t function correctly to get fuel to the carburetor for starting the string trimmer. If the primer bulb appears in good condition and it still won’t fill, check for a clogged fuel filter or fuel line.

Solution: Replace with a new primer bulb.

Clogged Fuel Line in an ECHO String Trimmer Will Cause Starting Problem

Old fuel sitting in your string trimmer can leave a gummy sticky deposit behind that restricts fuel flow. This can clog the fuel line and restrict the fuel flow your string trimmer requires to start.

Solution: Replace a fuel line on your ECHO string trimmer when it is cracked, kinked, or clogged.

Plugged Fuel Tank Vent in an ECHO String Trimmer Will Cause Starting Problem

The fuel tank vent allows air into the tank. Without a vent, the fuel tank will create a vacuum that won’t allow fuel to flow through the string trimmer.

A good indication you may have a fuel tank vent problem is when your ECHO trimmer runs for a few minutes and then shuts down and won’t start until you remove or loosen the fuel cap to allow air into the fuel tank.

When you tighten the cap and allow it to run and the string trimmer dies and fails to start until the cap is loosened, you most likely have a fuel vent problem.

Solution: Replace a plugged fuel vent.

Dirty Carburetor on an ECHO String Trimmer Will Cause Starting Problem

The carburetor regulates the amount of fuel that is mixed with air to create a combustion in the cylinder. Old fuel will gum up and clog the carburetor so it no longer functions properly.

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 or replace it with a new carburetor.

Depending on the model and age of the string trimmer you use, the price of a carburetor, and the cost of labor, it may be best to invest in a new ECHO string trimmer rather than put money towards replacing a carburetor on an old trimmer.

Bad Recoil Starter on an ECHO String Trimmer Will Cause Starting Problem

Your ECHO string trimmer uses a recoil to start the engine. A bad pulley; loose or missing spring; or broken clips can keep your recoil from working.

Solution: You can attempt to replace the spring and restring the recoil. If it does not work because other components in your recoil are damaged, such as the clips or the pulley, you are better off just replacing the recoil assembly.

Plugged Spark Arrestor in an ECHO String Trimmer Will Cause Starting Problem

You will find a spark arrestor in your ECHO string trimmer that can prevent it from starting. The spark arrestor is a small screen installed on the muffler to prevent hot materials from discharging causing burns or a potential fire.

The spark arrestor can get plugged with soot. When this happens, the string trimmer will fail to start.

Solution: Disconnect the spark plug boot. Make sure your engine is not hot. Remove the spark arrestor screen cover, gaskets, and spark arrestor from the muffler. Clean the screen with a wire brush to remove the soot. Reinstall.

If you are unable to clean it sufficiently or it is broken or has a hole in it, replace it with a new spark arrestor.

Flooded ECHO String Trimmer Will Cause Starting Problem

I have had customers bring their string trimmer to the repair shop because they can’t get it started. Many times it’s due to a flooded engine which isn’t too serious.

The engine can become flooded when the choke is in the closed position and the starter rope was pulled many times allowing too much gas into the carburetor.

It can also happen with the switch off and the starter rope being pulled multiple times or when the primer bulb is pushed too many times.

Solution: Use the following procedure to “unflood” your string trimmer so the engine gets the correct fuel-to-air ratio required to start and run.

How to Fix a Flooded Engine on an ECHO String Trimmer

• Turn the switch on to the run position.
• Move the choke lever to the open/run position.
• Press the throttle trigger while pulling the starter rope over and over. This can take anywhere between 5 and 15 pulls before it starts. Your ECHO string trimmer will sputter first. Continue to pull 2 to 3 more times and it should start.