Top 10 Causes of Troy-Bilt String Trimmer Failure

The string trimmer you have recently purchased has developed a personality disorder and refuses to keep running. In order to get you back to your lawn care duties, I have compiled a list of potential causes and solutions.

Inadequate fuel, air, and spark cause a Troy-Bilt string trimmer to start, stall, and eventually stop working.

Possible causes include a soiled carburetor, a blocked fuel filter, a plugged fuel line, a defective ignition coil, a blocked air filter, or a blocked spark arrestor.

Always refer to your Troy-Bilt operator’s manual for a complete list of safety guidelines to review before attempting any repairs. Removing the spark plug wire and waiting for the engine to cool down are both required steps.

troybilt string trimmer

Top 10 Causes of a Dead Troy-Bilt String Trimmer

Choke Problems with a Troy-Bilt String Trimmer

To start a cold engine, the choke is utilized to reduce airflow and increase fuel mixture richness. To keep running after the engine has warmed up, the choke must be in the open position.

If the choke isn’t readjusted once the engine has warmed up, the engine will splutter and eventually die from not receiving the correct fuel-to-air ratio.

See if the choke lever is in its normal position if your Troy-Bilt string trimmer starts but stops immediately. The trimmer will stop working if the choke lever is not set properly.

FIX: Turn it off once the engine is up to temperature.

Attached Air Filter for Troy-Bilt String Trimmer

If the air filter on your Troy-Bilt is clogged, the engine will stall and die in the same way as it will if the choke is left on.

An air filter is necessary for your Troy-Bilt string trimmer to protect the engine from dirt and debris. Maintaining its quality will allow air to flow through while blocking off dust and debris.

I think it’s best to change the air filter at the start of each season of grass maintenance. And then, periodically throughout the season, check and clean the filter.

If you need to use your string trimmer for a short while to get the job done, the air filter must always be in place. Doing so may damage the motor and void the remainder of your trimmer’s warranty.

Answer: Change the air filter. If your filter is severely soiled or broken, you should replace it. Please find enclosed detailed instructions for maintaining a foam air filter. If you have a filter that requires a different kind of filter, look in the instructions.

How to maintain the air filter in a Troy-Bilt FOAM string trimmer:

  • Take off the air filter and its housing.
  • You can use water and a mild detergent to clean the foam air filter.
  • Clean the filter by rinsing it under running water until the water comes out clean, squeezing out as much water as possible, and then letting it dry naturally.
  • After the filter has dried, lightly saturate it with clean SAE 30 motor oil. Remove any lingering oil by gently squeezing the filter. Oil should not be used with a foam pre-cleaner.
  • Get the filter back in place.
  • Put back the air filter cover.

Using a Troy-Bilt String Trimmer with Old or Corrupt Fuel

If you put stale gas in your Troy-Bilt string trimmer, it may stall and perform poorly. Ethanol, a fuel made from maize, is added to most gasoline to reduce pollution.

Although it’s better for the planet, it will seriously damage the Troy-little Bilt’s engine. As soon as 30 days after purchase, the gas/ethanol blend can start to deteriorate.

Corrosion of the trimmer can be caused by ethanol and the water it attracts. The varnish it leaves behind prevents as much fuel from reaching the engine.

Avoid using gasoline with high levels of ethanol because of the damage it can do to tiny engines. Fuel your Troy-Bilt string trimmer using unleaded gasoline that has an octane rating of at least 89 and contains no more than 10% ethanol.

Always choose for a fuel without ethanol, even if it means paying a premium.

Specifically, the 2-cycle and 4-cycle Fuel requirements vary depending on whatever Troy-Bilt string trimmer model you have.

  • Two-stroke motors can only run on a 40:1 ratio of gas to oil. To power their engines, Briggs & Stratton’s 2-cycle engines use a quality oil blended with unleaded gas. For every gallon of petrol, 3.2 ounces of oil are added.
  • Straight gasoline is necessary for 4cycle engines. Never combine with oil.

You should only use new gas in the string trimmer. The correct fuel and oil for your Troy-Bilt string trimmer can be found on this page.

The problem can be solved by removing the spent gas from the string trimmer. To stabilize the fuel, remove moisture, and clean the fuel system, fill the tank with new fuel that has been treated with a fuel additive such as Sea Foam Motor Treatment.

Turn on the trimmer and let it run for 5 to 10 minutes so that the fuel may circulate through the machine.

A Troy-Bilt String Trimmer with a Clogged Fuel Filter

The fuel filter is there to trap any dirt or debris before they might contaminate the fuel supply. The fuel filter for your Troy-Bilt string trimmer is located inside the fuel tank and is attached to the fuel line.

If you’re using unclean fuel, you should replace your fuel filter more frequently than once a year.

If you don’t change the filter, it’ll get so clogged up that not enough fuel will get through, slowing down or stopping your Troy-Bilt trimmer.

The gasoline filter should be changed. If the fuel is contaminated, you should switch to clean fuel.

Substitute a Troy-Bilt fuel filter:

  • Make sure no dirt or debris is about to enter the tank by wiping the area surrounding the gasoline cap.
  • You need to take off the top.
  • To remove the fuel filter from the tank, simply pull it out. The filter can be retrieved with the help of a clean bent wire or a pair of needle tip pliers.
  • The fuel filter should be disconnected from the tank’s supply line once it has been removed.
  • Insert the new gasoline filter into the fuel line to complete the installation.
  • You need replace the fuel filter inside the tank.
  • Be sure to replace the gasoline cap.

A Troy-Bilt String Trimmer with Clogged Fuel Lines

Deposits left behind by stale fuel can cause blockages in fuel lines. By doing so, you restrict the fuel’s ability to move through the line and shrink the opening.

When this occurs, the gasoline line must be disconnected and replaced with another fuel line of the same size. If the gas line is dry, cracked, or bent, you need to get a new one.

Troy-Bilt String Trimmer with Blocked Fuel Tank Vent

A vent in the fuel tank of a Troy-Bilt string trimmer is necessary because the fuel is heated and must be cooled by air. If you block this vent, the tank will develop a vacuum, preventing fuel from reaching the carburetor.

If you’ve checked to make sure you’re using a good fuel filter and the fuel line is clear, but you’re still not getting fuel to the carburetor, the fuel tank vent may be clogged.

The pressure in the tank can be checked with a pressure gauge to ensure there is no vacuum. However, a gasoline line pressure gauge isn’t something you’d typically find in a home toolkit.

If you don’t have a pressure gauge but want to make sure your gasoline tank is venting correctly, follow these steps.

This easy test might help you determine if the vent in your gasoline tank needs replacing.

  • Start the trimmer by releasing air from the fuel cap. Please keep the fuel tank from leaking.
  • To get the engine going, you need to start it. It may be a vent issue if it works smoothly and never sputters or dies.
  • You can verify the vent as the source of the problem by trying to reproduce the situation.
  • Make sure the gas cap is secure before turning on the string trimmer. The fuel tank vent should be replaced if the vehicle loses power, stalls, and won’t restart unless the fuel cap is loosened.

Most Troy-Bilt string trimmers include a fuel tank vent that is integrated into the fuel cap.

Unclean Troy-Bilt String Trimmer Carburetor

The carburetor on your Troy-Bilt string trimmer ensures that the right amount of air and fuel are combined during combustion. When the channels get clogged up, the tiny parts stop working properly.

Inadequate fuel-to-air ratios might cause the string trimmer to run poorly or perhaps shut off altogether.

You may try cleaning the carburetor to see if it helps. If cleaning your Troy-Bilt carburetor doesn’t fix the problem, you may need to rebuild it (if rebuild kits are available for your model) or replace it.

If you need a string trimmer and are thinking of repairing the carburetor on yours, you might want to look at how much a brand new Troy-Bilt costs instead.

Whether or whether you should invest in a brand-new trimmer depends on factors such as the trimmer’s age, model, and price.

Troy-Bilt String Trimmer with a Grimy Spark Plug

Over time, carbon residue will accumulate on the spark plug and make it unclean. The result can be misfires at the plug, resulting in sporadic starting issues.

It’s also important to check for things like a spark plug wire that’s too loose and a spark plug gap that’s too large. Your Troy-Bilt may also have a problem running if you have any of these parts.

ANSWER: A dirty spark plug can be cleaned with a wire brush and reused if possible. If that’s the case, it’s probably best to just get a new trimmer altogether.

It’s a low-cost component that plays a significant role in your string trimmer’s optimal performance.

Check that the spark plug wire boot is properly attached and that the distance between the plug and the spark plug is as specified by the manufacturer.

Faulty Ignition Coil

Ignition coils are prone to malfunction due to winding separation and subsequent shorting. No spark will be produced by the spark plug because insufficient voltage is being supplied. The Troy-Bilt will stop working after being run for a while if you do this.

The problem can be solved by using an ohmmeter to look for a break in continuity and thus identify a defective ignition coil. If you detect a crack in the ignition coil, you should replace it.

Troy-Bilt String Trimmer With Its Spark Arrestor Plugged

At the very base of the muffler, you’ll find a small metal screen. This will keep you safe from burns and fires caused by the trimmer’s hot exhaust material blasting out.

As carbon accumulates on this tiny spark arrestor screen, engine performance will suffer.

The spark plug wire needs to be disconnected. Take off the silencer. Be sure to take your time when removing the spark arrestor’s cover and screen. Check for damage to the spark plug.

If it’s still in good shape, you can clean it with a wire brush and put it back in service. Still, a new spark arrestor screen must be installed if the old one is ripped or otherwise compromised.

If you are unable to locate the spark arrestor screen or if you are still having issues with your Troy-Bilt string trimmer, please contact your nearest Troy-Bilt service center.

Carburetor adjustments are best left to certified technicians at a dealership or similar establishment.