Why Won’t My Weed Eater Start?

Help! Why Won’t My Weed Eater Start?

We’ve all been there- we store away our string trimmer at the end of the growing season and when it comes time to fire it up again in the spring, the darn thing won’t start.  In my household it’s cause for a fair amount of frustration, prayers to the lawn gods, and the occasional expletive each spring as I prep, prime, and attempt to get items that have been stored for months started again.

But what’s even more frustrating is when your weed trimmer has been working just fine and then, simply put: the weed eater won’t start. No matter the circumstances, before you load it up for a trip to the hardware store, look over the following helpful hints that might just get you back up and running fairly quickly- and save you both time and money. Most weed wackers, whether handheld or walk-behind, are simple enough in their design to troubleshoot fairly easily.



Assuming your gas is topped off (don’t laugh, empty gas tanks happen to the best of us), make sure you have mixed fresh fuel with the correct ratio of 2-cycle oil (40:1, or 1 gallon fuel to 3.2 ounces oil), or you run the risk of seizing up the engine over time. Your fuel should also be less than 90 days old, as it might not move fluidly through the carburetor to the spark plug and fuel filters can more quickly become clogged as well (although clogged fuel filters are a rarity).

If all of the above is set, remember that oil and gasoline separate over time and it is recommended that you shake your mixed fuel before topping of your tank. Also swishing around the existing fuel in the tank before getting started ensures that not just straight gasoline or oil is primed through the carburetor.

Attempting to start your engine too many times, or turning your trimmer on it’s side, can also resulted in a flooded engine. If you think this might be the case – set your choke lever to ‘run’ and pull the cord to burn off the excess fuel. You may also need to allow your weed wacker to rest for 10 to 15 minutes before trying to start again.


If you engine is trying to run, or starts and quickly stops, you might want to do a quick air filters check. Like all things with an engine, you need air for your initial spark- and if oxygen cannot move readily through the system you will have problems both starting and keeping your weed eater running.

Your air filter is there to do just that, filter the air, so it makes sense that sometimes this does get grimy and blocked up. Cleaning, or replacing, an air filter is incredibly simple and straightforward.

To see just how simple, watch below:


Even with poorly mixed fuel and dirty air filter, you should get some sort of response from the engine. If you don’t even get a half-hearted splutter, then the problem may lay with your spark plug. Dirty spark plugs are a common problem and will hinder the ‘spark’ that helps fire up an engine. Luckily, this is a simply fix, and by removing the plug and cleaning it with a wire brush and a little gasoline- you may solve well over half your starting issues.

Once you have the spark plug removed, look it over carefully for cracks in the ceramic, and check the gap as well. If your plug has a crack, you need to get a new one as the spark isn’t going to make the jump to get started. The same goes for the gap. The gap between the plug nodules should measure .025” to .030” and anything larger, or smaller could be causing you issues and needs to be adjusted or replaced.

Spark plugs are very inexpensive and if you have taken all these precautions, or even replaced your plug, then you might have a bit more of a complicated problem that requires a little more knowledge of where parts are located on your model.
If you need help removing your spark plug, watch below for some quick, handy tips:


The carburetor is the heart of an engine’s starting mechanism, and if something goes wrong with it, then it’s going to be pretty hard to get your weed wacker started. If you have a primer button, this is what it is located on, and it sprays fuel into the reservoirs that help your spark plug fire up the engine.

A lot of the time your carburetor may just need a thorough cleaning to get rid of the dust and grime that has built up around it and in it over the years. This process may also include having to replace it since once you take it off you may find it looking amiss. In my case, a small piece of plastic housing had broken loose and had actually lodged into the carburetor, calling for a new one.

Occasionally only the primer bulb weathers and cracks or breaks as well, and these are simple and cheap to replace.

Whole Carburetor replacements are fairly inexpensive and are worth the purchase rather than setting out to replace the entire weed eater itself.

For a step by step removal and cleaning guide, watch below:



If you have an electrical weed trimmer, then the most obvious troubleshooting is where you need to start: the power source. Check that all electric cords are plugged in securely and that the electrical outlet itself is drawing power. Do this also for battery powered trimmers where the charge occurred and that the charger is also working correctly.

Also, check your fuses and circuit breaker to make sure no problems exist with the power source.
Extension cords can also become faulty over time, and if they do not have a light check built in, you might want to test the weed wacker with another cord to rule this out.




CLEAN AIR FILTERS: Get rid of dust!


PRIMER BULB: Any cracks?




4 thoughts on “Help! Why Won’t My Weed Eater Start?”

  1. I replace the carburetor , fuel lines , fuel filter, spark plug, and my weed eater want not to start. The magneto is working well because I have the spark plug tester and give normal spark. So I don’t know what could be.
    Beside that I’m using the jump starter with my drill and nothing, not even sput a little.

  2. RYOBI CS26
    Recently replaced the carburetor on this string trimmer along with a new fuel filter. Started right up and ran great on two occasions, about 45 minutes each, performed perfectly.
    Start up on the third usage, ran great for about 15 seconds and then quits.
    This occurred many times, same results.
    Replaced the fuel line with a new fuel filter, cleaned out the gas tank. Again, starts up and runs great for about 15 seconds and again it quits on me.
    Seems it runs on the fuel used to primed the engine, but is being starved of fuel for continuous operation??
    Any suggestions? Buy another carburetor?

  3. I would bet it is your fuel system. Start by draining the fuel tank access the fuel filter in tank and verify it is not plugged. Next trace your fuel lines and verify they are whole and not leaking/connections. If all that is in order then u most likely have a plugged carburetor. There is an internal screen that u can access by removing the Carburetor. Note: take pictures before u disassemble for ease in reassembly but once that screen is blown out, rinsed or soaked reassemble and start.


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