Why does my weed eater keep dying? (And how do I fix it?)

Most weed eaters have a 2-cycle engine, but others have a 4-cycle engine. They’re very useful in their ability to easily trim tough weeds and also trim the little uneven grasses left behind by your lawnmower. A weed eater is also very useful in cutting grass in hard-to-reach places like around trees and landscaping.

Operating a weed eater comes with its own challenges and sometimes the weed eater may have a mind of its own and randomly act up like when it starts then dies for no good reason. So, why does my weed eater keep dying? There are many reasons why your two-cycle engine keeps dying on you. This includes gas problems, clogged air filter, blocked carburetor, clogged spark arrestor, or clogged fuel filter. Fortunately, it’s very easy to fix these problems so you can go back to maintaining your lawn in no time.

 

If the engine doesn’t have good air circulation, clean fuel, and a spark, it won’t start, but it may run for a while if the air and fuel flow is restricted. It’s easy to restore the airflow, but if the fuel flow is restricted, it will be more time-consuming since you may be forced to disassemble the carburetor and clean it.

Problem	Cause	Fix
Gas problems	No gas in the fuel tank, use of the wrong fuel, cracked prime bulb	Put enough fuel in the tank, use ethanol-free gas or pre-mixed fuel and replace the cracked prim bulb
Fuel filter	Clogged fuel filter	Drain old fuel, clean or replace the fuel filter
Air filter	Clogged or dirty air filter	Clean or replace
Spark plug	Carbon buildup	Replace
Carburetor	Carbon buildup or corrosion	Replace
Exhaust	Clogged exhaust screen	clean

How to fix my weed eater keeps dying

Gas problems

When you’re dealing with gas-powered weed eaters, you need to first check if there’s enough gas in the tank. If there’s enough gas, check if the primer bulb is filling properly before starting the engine because it tends to dry and crack with time, so make sure it’s not allowing air to pass through when you depress it. It could also be the fuel mixture you’ve used is causing the problem. Most manufacturers recommend that you use ethanol-free gas or gas with only 10% ethanol because it can really mess up your engine. You can also buy pre-mixed fuel that has a much longer shelf life than your homemade fuel mixture.

Fuel filter

A clogged fuel filter is mostly caused when you leave fuel in your weed eater during the winter when it’s not in use. Some of the ingredients in the fuel evaporate leaving behind a thick sticky sludge that clogs up the fuel filter which causes the engine to stall. If you left old fuel in the fuel tank, the best solution is to drain it out from the fuel tank and clean or replace the fuel filter.

Air filter

The engine draws in air that it uses for combustion through an intake port. The air filter is designed to capture dust, debris, and pollen before it enters the combustion chamber, and if it’s dirty and clogged there will only be partial combustion which will result in your weed eater starting then dying. Depending on the model, you just need to unscrew a single screw or turn a plastic knob to remove the air filter cover and clean or replace depending on the type of filter you’re using which is easy and inexpensive to replace.

Spark plug

Small engines use one spark plug to provide that tiny electrical burst that it produces to ignite the fuel and oil mixture in the combustion chamber. After some time the spark plug can get a build-up of carbon and other residues that can cause it to misfire. This is more common with the 2-cycle engine that tends to leave a carbon residue behind, especially if you don’t use the right gas to oil ratio. If the spark plug is deformed or cracked, you should replace it.

Carburetor

The carburetor is the place where the fuel and air combine and over time there’s corrosion or a carbon buildup that forms which prevents it from performing properly. If you see signs of corrosion or excessive rust in your carburetor, you’ll need to replace it. You can DIY or take it to a lawnmower repair shop for a quick fix.

Exhaust problem

This is the least likely issue but one you need to also check. The same way your weed eater needs proper air intake is the same way it needs to release the air that flows through it otherwise there will be serious problems. An air buildup can cause the engine to shut down quickly and this can be caused by a fuel screen that has become gummy over time, especially with frequent use. You’ll need to take apart the exhaust to clean the exhaust screen.

Conclusion

There are many reasons why your weed eater keeps dying and there are easy fixes that you can easily handle on your own. The best thing you can do to avoid all these problems is to ensure you properly maintain your weed eater and store it properly when not in use. If the problems persist or become worse, there could be something deeper going on with the engine so it’s best to take your weed eater to the professional.

FAQ

What causes a weed eater not to stay running?

If there’s not enough air in the combustion chamber because the air filter is dirty, there will be partial combustion and the weed eater will sputter and die. The spark arrestor could also be clogged so the engine can’t get rid of all its exhaust gases.

Why do weed eaters smoke?

Weed eaters can either produce black, white, or blue smoke which can be caused by exhaust buildup, improper gas to oil mixture, mechanical components malfunctioning, and the engine not running at the proper temperature.