How to service petrol hedge trimmer

If you own a car in the UK, then you know that it needs to be serviced in order to keep it running properly. Even by law, we are required to have it go through its MOT to make sure that it is less likely to break down on us when we need it the most.

Although there is no legal requirement to keep your petrol-powered tools well maintained, it should go without saying that they need to be serviced properly. This goes for all these types of tools, no matter if it is a lawnmower, multi-tool, auger, or anything else. If you don’t take care of your tools, they will inevitably break down.

So, with this in mind, you have two choices- either take it to a professional and pay them to do it or save yourself a few quid and have a go at it yourself. If you have money to burn, then by all means, take it to a pro, but if like the rest of us you’re not rolling in dough, this guide is here to teach you how to service a petrol hedge trimmer. This will keep your machine working and avoid the need to do this 🤣

Servicing a petrol hedge trimmer- things you’ll need

To service a petrol hedge trimmer, you’re going to need a workbench or table, as well as the usual hand tools that you can find in your toolbox such as spanners, screwdrivers, etc. For sharpening the blades, you’ll require an angle grinder or file, but you can find out exactly how to sharpen a hedge trimmer blade in our article devoted to that very subject. Some cut resistant gloves and eye protection are also definitely needed for the process.

Make sure the hedge trimmer has been thoroughly cleaned before starting any maintenance. This is for a number of reasons, not least of which is stopping getting dirt and debris into the inner workings of the machine.

Your hedge trimmer blades should be cleaned after every time you use the tool, as tree sap can build up on there and this leads to the blades becoming dull. Dull blades can lead to larger problems as the motor and other parts have to work much harder to do their job. There are sprays that you use to clean sap off your blades as you can see this guuy using-

At first glance

Before taking anything apart, you might be able to see some things that need repairing by giving the hedge trimmer a once over. Things like the rubber parts can be checked to see if they are still in good condition or if they are split or torn, and screws and bolts tested to see if they are tightened up properly.

The blade can be inspected for sharpness and can be tested with a piece of paper to see if it will cut it easily. The blade also needs to be able to move smoothly, but won’t be able to if the screws have been tightened too much, so try to move it around with a gloved hand to check this.

Servicing a petrol hedge trimmer- things to check

1. As already mentioned, check the cutting blades to see if they are moving smoothly, and adjust the screws if they are not. You don’t want the screws too loose though, they should be as tight as possible without affecting the movement of the blades. This is true for electric and cordless hedge trimmers too.

2. Keep the blades clean and sharp. You can sharpen your hedge trimmer cutting blades fairly easily by removing the blade and locking it into a bench vice. Then use a file and make downward passes on the cutting edges of the teeth before lifting the file and returning to the start point. Never file up and down as it is counterproductive. You can use an angle grinder to get the job done faster, and even a bench grinder if you have the skill, but you have to be careful not to grind away too much. In this clip, the man uses a dremel tool which is also a viable option-

3. Make sure your air filter is clean. This is a fairly easy maintenance job, but one that shouldn’t be overlooked. Your motor needs a good flow of air to perform at its best and will end up overheating and breaking if the air filter is not maintained properly. Air filters are usually easy to remove, sometimes with only a press of a switch. Once removed from the machine, you can use an air compressor to clean the filter, or simply blow on it. Knocking it against the table or bench will help to free up the debris that has clung on there too.

4. If the filter is really dirty, and you can’t blow or knock it out of there, you’re going to have to replace it. Thankfully, they are not overly expensive and usually very easy to find and to be honest, you should always have a couple of spares lying around if you own a petrol pole hedge trimmer, petrol brush cutter, petrol chainsaw, etc. After all, everyone knows-

5. Once a year, I would suggest draining the old fuel out of the engine and replacing it. How you will do this will depend on the design of your petrol hedge trimmer. If your model has an easy to access external fuel line, you can simply unplug it and drain the fuel. If not, you’ll have to locate the drainage plug and unscrew it. The process for doing this is much the same as when servicing a petrol lawn mower, so please check out our article on that as it goes into more detail in the process.

6. At the same time that you change the fuel, you should check, clean, and if needed, remove and change the spark plugs. This is an easy job and only requires you to have the right kind of spanner. Your hedge trimmer should come with instructions that show you how to locate the spark plug, air filter, and every other important part of your tool that will need servicing. Top brands usually have full instructions on their websites and even YouTube videos on the subject too.

And that’s all you really need to know. Check the screws, plastic and rubber parts, and blade, every time you use the tool, change the fuel at least once a year, but more often if the tool is sitting unused for over 3 months, keep an eye out for leaks, and clean and change the air filter and spark plug. Maintaining these things will ensure that your tool keeps on working properly, and give you much better value for money.

About Terry Smith

I’m Terry Smith from, a professional landscape designer, hobbyist gardener, and barbecue fanatic with 20 years experience building and restoring. So as you go through my site you'll watch me document some of the professional garden installs I make as well as the major projects I take on at home. While sharing those experiences and guiding you, I'll be recommending some great tools I use to enable this along the way so you can really buy in confidence. Always feel free to pop me a message:

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