How to Fix a Homelite trimmer that starts then dies

Does your Homelite trimmer turn on but won’t stay running?  Don’t worry, it’s a very common issue for small engine equipment.

This can happen in either new or old trimmers. In the case of old trimmers, the issue is mostly related to some fault in the carburetor. Whereas when it comes to new trimmers, the most common reason behind this issue is an unadjusted carburetor.

Key Takeaways

• Replace Fuel if it has been sitting on the tank for a while.
• Clean the Carburetor (Screen located next to the primer bulb must be debris free)
• If cleaning doesn’t work, then replace the carb.
• Check if the Fuel Filter is Clogged, if it is, replace the filter.

1. Stale Fuel

It is important that you keep the fuel clean and fresh for the trimmer to work properly. If the engine is provided with dirty or poor-quality fuel, the energy produced from the combustion won’t be enough to keep the engine running.

So, before you do anything, make sure that the fuel is meeting the requirements of a Homelite trimmer’s engine (most Homelite trimmers require a 50:1 fuel ratio but check your manual to confirm), if the fuel has been on the trimmer for a while without being put to use, then go ahead and replace it.

2. Clogged Fuel Filter

If the fuel inside your trimmer was sitting in the trimmer’s fuel tank for a very long time, then it is very likely that the fuel filter may also be clogged. This is because over time, some of the fuel evaporates, and the part left becomes sticky. This sticky part of the fuel causes the fuel filter to clog. 

It is recommended to change the fuel filter after every 40 hours of use, so even if your filter isn’t the main issue, it’s not a bad idea to replace it (costs less than $5 a piece).

How to Replace the Fuel Filter:

1. Empty the fuel tank if there is any fuel inside it.
2. Use any long-necked tool to take out the free end of the longer fuel line from the fuel tank.
3. The fuel filter is connected to that end. 
4. Remove the old fuel filter and connect the new one.
5. Insert the fuel filter along with the fuel line back into the fuel tank.

Here’s a video Tutorial –

3. Carburetor Need Adjustment

Note – Some Homelite Trimmers might not have an adjustable carburetor, in which case your only option is to either clean or replace your carburetor.

The carburetor controls the ratio of the fuel mixture that goes to the engine. 

You can find two screws in your carburetor, a LOW screw, and a HIGH  screw. The LOW screw is labeled with an L and the HIGH screw with an H. 

The LOW screw adjusts the fuel mixture at the idle state whereas the HIGH screw adjusts it at the high state i.e. while giving throttle. 

When the adjustment is not done correctly or the screws are not tuned, then the air-fuel mixture does not reach the engine in the correct ratio, resulting in the trimmer refusing to run. 

We have a complete guide on how you can adjust the screws on your Homelite trimmer. But to summarize – Make half turns on the L screw if the trimmer is shutting off on idle and 1/2 turns on the H screw if the trimmer is bogging out on the throttle. It’s a trial and error game, keep making half turns and find the sweet spot for both the crews.

4. Clean the Spark Arrestor

Sometimes, trimmers die out soon after starting due to a blockage in the exhaust. This blockage can occur based on the fuel and the conditions in which you are operating your trimmer. Basically, carbon starts to build up in the screen and so it needs to be cleaned.

How to Clean the Spark Arrestor?

1. Unscrew and remove the back cover.
2. Remove the screen from inside the silencer.
3. Use a carbon cleaner and then use a wire brush to clear all blockages.
4. Put the screen back inside the silencer and close the trimmer.

5. Clogged Carburetor

Fuel from the fuel tank passes through the carburetor before going to the engine. Therefore, it is important that the fuel does not get blocked in the carburetor. 

The primer bulb, which is pumped in order to get the fuel flowing from the fuel tank to the carburetor, is attached right next to a screen. 

So the fuel must pass through this screen smoothly. For this purpose, the screen must not have any debris or dirt on it. You need to open the carburetor to make sure the screen is clean, follow the steps below (or find a video tutorial on youtube) –

How to Clean the Carburetor:

1. Take off the air filter from the side of the trimmer.
2. Mark the positions where the fuel lines are connected to the carburetor and then disconnect them from the carburetor.
3. Remove the carburetor.
4. Unscrew and remove the pumping side of the carburetor to reach the screen.
5. If the screen is dirty, clean it. You can do so by removing it by using some kind of a pick and applying a little pressure to take the screen out. Then use carburetor cleaner to clean the screen. 
6. Open other sides of the carburetor and clean them as well.
7. Put the screen back and screw back all the sides.
8. Connect back the carburetor. Make sure you put the gaskets in their correct locations.
9. Try running the trimmer. You might have to adjust the carburetor again so repeat step 03. If the trimmer runs fine, then close the air filter. If not, proceed to the next step.

6. Carburetor Replacement

How to Replace the Carburetor:

1. Remove the air filter and disconnect the fuel lines from the carburetor. Make sure you remember where each fuel line was connected to the carburetor.
2. Remove the old carburetor and put the new one in its place. 
3. Connect the fuel lines to the new carburetor at the right positions and make sure they are secure.
4. Slide the air filter back on the trimmer.

Now you have a brand new carburetor installed in your trimmer. Start the trimmer and the problem should now be gone.