7 Reasons Why Troy Bilt Trimmer Starts And Dies (How To Fix)

Troy Bilt Trimmer Starts And Dies

Troy Bilt and Craftsman trimmers are made by MTD Products, which means they have compatible attachments. Several other companies also have the same size. Sadly, having cross-compatible attachments won’t save you from every trimmer problem.

When a Troy Bilt trimmer starts and dies, there are several possible culprits. I will walk you through the top seven causes so you can get back to your accessories and make your yard look incredible.

Why A Troy Bilt Trimmer Starts And Dies

A Troy Bilt trimmer starts and then stalls because of fuel or carburetor issues. Fuel lines can break or become clogged due to a dirty fuel filter that needs to be changed. Also old, contaminated fuel can become sticky and clog the carburetor diaphragm causing power issues. The carburetor needs to be cleaned as part of regular maintenance.

Troy Bilt Trimmer Starts And Dies

The trouble of starting and stopping trimmers is not uncommon, nor is it exclusive to Troy Bilt. There are quite a few things that can lead to this particular problem.

Fortunately, most of the root causes are relatively easy to fix. In many of these scenarios, the part you need to clean or replace is obvious, and anyone can handle it with few tools and no specialty training.

The list below explains the 7 reasons why Troy Bilt Trimmer Starts and Dies:

1 – Fuel Cap

Fuel cannot flow in a vacuum. For your trimmer to run, the gas has to be able to move from where it starts in the tank. To pull fuel out of the tank, something has to take its place, and that something is air. Where does the air come from?

Your fuel cap has an air intake. When the air vent in your fuel cap gets blocked, it causes a vapor lock, which is a fancy way of saying vacuum. So long as nothing can flow in, nothing can leave the container either, which also means it is effortless to check.

Loosen up your fuel cap and start the trimmer again. The loose cap will allow air to move into the tank, replacing the spent fuel. When this trick works, you either need to clean the lid you have or, in many cases, replace it.

2 – Fuel Filter

Fuel can get contaminated in several ways. When you open the tank, debris can get in, or sediment from the bottom of a gas container are two easy examples.

Regardless of how impurities get into a gas tank, the way to prevent them from building up inside the engine is to put a filter in place.

Your fuel filter, like an AC filter, will eventually collect enough debris to become clogged. Weedeater.com recommends changing your fuel filter once a year.

However, if your trimmer starts and stops, you may need to check and replace it sooner.

To change the fuel filter, first, drain the fuel. You should be able to pull the fuel line and filter out through the gas tank opening.

After that, you can swap the filter for a clean one and put it back.

3 – Bad Gas

Fuel that is old, contaminated, or otherwise wrong for your machine will cause it to stop. Hopefully, you catch this issue before you run the engine.

When bad fuel is the issue, all you can do is drain and clean the tank, refill it with good fuel, and hope for the best.

Sometimes it works, and other times you may need to replace the engine. Sour gas is also a leading cause of carburetor clogs.

4 – Air Filter

When the air doesn’t flow through your trimmer engine, it’s a lot like when the fuel doesn’t flow. You may get the machine started thanks to the air already inside, but it will stall out almost immediately.

You should change the filter roughly once every three months when you’re using your trimmer regularly.

Changing an air filter is like changing a fuel filter. There’s a cover over the filter, and it has a knob or clip, depending on your model.

Swapping the air filter is as easy as opening that cover and removing the dirty, clogged filter. All you need is a replacement filter that fits your make and model.

5 – Spark Plug

If you’re lucky, the spark plug is the problem. Inspecting a spark plug for damage is usually easy as it is visually apparent if cracked or corroded.

According to Mitchell Tractor Co, you should change a string trimmer spark plug after every hundred hours of use.

Check your owner’s manual for the correct gap setting. Pull the boot back with your fingers. Detach the spark plug, then replace it with a new one. Finally, put the boot back and reset your plug.

6 – Carburetor

If you are running an electric string trimmer, then the fuel and carburetor are not the issue. Otherwise, a worn-out carburetor diaphragm may be the cause of your start and stop power problem.

It’s always wise to clean out the carburetor first, but since you should be doing this as a part of routine maintenance, let’s look at the issues most likely to cause stalling.

First, check your idle speed. If your engine isn’t idling fast enough, then it won’t continue running. The screw to adjust idle speed should be under/behind the air filter.

You can change it with a basic screwdriver, but don’t turn it more than a quarter turn for each adjustment. If the engine still stops or sounds wrong, check the diaphragm.

You’ll need to drain out the fuel to reach the carburetor diaphragm. It should be on the inside, on one of the sides. You’re looking for a small piece of plastic with flaps.

If the flaps are worn, it won’t regulate properly and needs replacing. I recommend this RA Brand Tool Kit with carburetor from Amazon.

RA Brand Tool Kit Rep Walbro 500-500 Diaphragm Carburetor + Plastic Box
  • Tool Kit Replace 500-500 Diaphragm Carburetor
  • For Chainsaw , Blower , Trimmer

Last update on 2022-12-05 / Affiliate links / Images from Amazon Product Advertising API

Regrettably, you will need a professional assessment if you cannot solve a carburetor problem with a new diaphragm, regular maintenance, or adjustments to the idle speed.

You may likely need to replace the entire carburetor or at least have it refurbished.

7 – Clogged Exhaust

Exhaust is all too easy to forget about. Just as the fuel and air need a clear flow for intake, there needs to be an exit on the other side.

Debris from yardwork can easily clog up the exhaust port. Clogged exhaust is arguably the easiest fix since you can see inside the exhaust easily.

Ensure your machine is off. If necessary, use canned air for added pressure to help blow out any debris you can’t remove by hand.

Helpful Tips To Know About Why Troy Bilt Trimmer Starts And Dies

Repairing most of the problems that cause your trimmer to die right after it starts is incredibly easy. Often you won’t need more than a screwdriver and a new part.

Here are some other helpful tips to know about why a Troy Bilt trimmer starts and dies.

  • Always keep your owner manual. You would be surprised how often you can repair a simple tool like a string trimmer. Though it seems intimidating at first, you’ll find it’s straightforward tech. If you’ve lost this essential, you can find downloadable copies from Manuals Online.
  • You can also check your trimmer for air leaks in the fuel line. Since this requires a unique pressure gauge, I didn’t include it with the simple fixes above.
  • Another place that a less simple issue can occur is the wiring in the on-switch. Bent, broken, and corroded wiring often leads to poor electrical connections.

Final Thoughts

String Trimmers are essential for keeping your yard looking nice. Since Troy Bilt, Craftsman, and several others have compatible accessories, you’ll have no trouble getting everything the way you like it, so long as you can get the trimmer to stay on.

Whether it’s a fuel cap or carburetor, now that you know what to look for, you can get back to tidying up the yard faster.

Drew Thomas

My name is Drew Thomas and I’m the creator of Fun In the Yard, your one stop site for all your outdoor games, sports, party activities, outdoor gear, and lawn & gardening tips.

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