How to Start a Petrol Strimmer

Emma Loker Headshot - DIY Garden
Written by: - Gardening Expert
how to start a petrol strimmer

Want a well-manicured garden? Don’t we all! This look would be impossible without your petrol strimmer keeping the weeds out of your way and the lawn edging crisp. 

But to use it, you’ve got to know how to start it. This article takes you through cold-starting your petrol strimmer and firing it up when it’s warm, too!

How to Start a Petrol Strimmer – Cold Start

8 straightforward steps. That’s all it takes to get your petrol strimmer going. Follow these, and you can’t go wrong!

1. Mix Fuel

Funnily enough, a petrol strimmer won’t work without fuel. But it’s not just petrol that the strimmer requires. You’ll need to mix unleaded petrol with semi-synthetic 2-stroke oil at a ratio of 40:1. 

Your petrol strimmer should have come with a lidded measuring jug. You’ll likely find guidelines on the side, so use these for reference! Put the lid back on the jug and give it a good shake. 

2. Fuel Up!

Fuel up your strimmer with your pre-mixed fuel. Take off your strimmer’s fuel cap and pour your mix in. The tank should end up being ¾ full. No more, no less.


3. It’s Time to Prime

Press down on the priming bulb between 5 and 8 times. You’ll require fewer starter cord pulls to start the strimmer after this. Fuel should be travelling into the priming bulb at this point. 

If it’s not, there’s a problem. Check the troubleshooting tips further into the article for guidance. 

4. Turn it On

Now, it’s time to turn it on. Reposition the switch so it’s on the “On” setting. This may appear as an “I” on some strimmers.

5. Give it Some Throttle

The next thing to reposition is the choke. Change this to the “Start” position and squeeze the throttle lever. Only do this once! 

6. Get Your Strimmer in a Sturdy Position

Before you even think about moving onto the pull-start, you’ll want to place your strimmer on the ground in a sturdy position. Ensure the pull-start is facing you and the cutting area isn’t making contact with anything.

7. Pull Start

Then, place your left hand on the strimmer neck and use your right to grab hold of the pull start. Gently bring the pull start towards you until you feel resistance, then tug hard 3 – 5 times until the engine starts to roar. 

The best way to start up your strimmer is using a vertical pulling motion. Keep the rope taut, not letting any slack touch the strimmer casing.


8. Increase the Airflow

Increase the airflow into your strimmer by moving the choke to “Run” or “Open.” Press down on the throttle a little, then leave it to run for around 40 seconds. Now, it’s time to get strimming!

What To Do if the Strimmer Doesn’t Start

Ok, so you’ve followed the instructions precisely, but your strimmer is sitting there silent. There are 5 things you can do to check the condition of your petrol strimmer. 

Troubleshooting Tips

Tip 1: Check Your Fuel Mix

Measuring your fuel mix wrong is an easy mistake to make. In fact, it’s the most common blunder. Did you definitely add 40 parts unleaded to 1 part 2-stroke oil?

If there’s no mistake there, consider the age of your petrol. It should be less than 6 weeks old. Your petrol strimmer won’t like stale fuel. 

Tip 2: Tweak the Carburetor Settings

There’s a delicate balance between fuel and air. This balance needs to be maintained for the strimmer to work. 

You can tell if the balance is wrong because the start is slow. It doesn’t have its usual roar! Find your strimmer’s adjustment screw, then turn it as far clockwise as possible. Rewind it 1.5 – 2 turns, and try the starting process again.

Tip 3: Save a Flooded Engine

If it still has no life, check that the engine isn’t flooded. This happens if you pull the start mechanism too many times. 

Don’t worry, there’s an easy solution. Just check the spark plug isn’t damp. Take the spark plug out and let some of the fuel evaporate if you suspect it’s flooded. Put the plug back, then try the start process again.

Tip 4: Check for a Spark

Expose the spark plug by taking off the top cover. Take out your spanner and remove the spark plug wire and the spark plug itself. 

Then, holding the spark plug’s boot end, tap its electrode tip onto a metal surface. Switch your strimmer on if it’s not already, and yank the pull start with your spare hand. The spark plug will produce blue sparks if it’s in good working order.

Tip 5: Inspect the Tank Filter

The tank filter can sometimes stop fuel from travelling into the engine. Check there’s fuel in the priming bulb. If not, open your strimmer’s fuel tank and reposition the fuel filter, so it’s not as close to the neck of the tank. 

Then, try to start your strimmer again. 

If you’re still struggling to fire up your strimmer, it’s time to call in an expert. 

How to Start a Petrol Strimmer – Warm Start


You’ve already got past the cold start stage, and you’ve had your strimmer up and running. You’ve switched it off momentarily, but now you’re ready to continue. 

Firing up your petrol strimmer from warm is easy peasy. Even a child could do it – although I wouldn’t recommend it! Just position the Start/Stop switch to “Start”, place the choke on “Run”, then yank the starter cord. Once the motor is running, you’re good to go! 

Let’s Get Strimming!

You’ve almost achieved that pristine garden you’ve always wanted. If you’re starting your petrol strimmer from cold, follow the 8 easy steps above, and use the troubleshooting guide if it’s not playing ball. 

If you’ve already got your strimmer going, what are you waiting for? Perform a warm start, and keep up the good work!

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