Grass trimmer maintenance
For long-term top performance, your brushcutter or grass trimmer needs regular maintenance. Find out the key points along with troubleshooting tips.
13.07.2023
Before you start: important points about grass trimmer maintenance
Grass trimmers use a rotating mowing line to quickly cut long grass and get it under control; brushcutters function similarly, and may use blades to tackle the toughest undergrowth. The maintenance steps required are the same in both cases, and the first step is always to read carefully through the operating instructions. you will find information about the most important maintenance tasks there.
Only perform maintenance tasks as advised and described in your operating
instructions. For all other repairs and servicing visit your STIHL dealer, who has the expertise to safely restore your tool to working condition.
Checking the cutting tool
Your grass trimmer works with mowing heads that can be quickly and easily replaced as required. The condition of the cutting tool is all-important to the smooth operation of your grass trimmer, so you should regularly check it as part of your grass trimmer maintenance routine. It is crucial to note that the various types of mowing heads have different requirements:
- For a mowing head with line (e.g. AutoCut, SuperCut): open the mowing head and check that the line is wound correctly – the lines should not cross over each other. If they are not correctly aligned, wind a new genuine STIHL mowing line onto the head.
- Mowing head with plastic blades (PolyCut): inspect the mowing head for cracks – these signs of wear let you know when the tool needs to be replaced. All three blades of the PolyCut must always be replaced as a complete set.
- Metal cutting tools (e.g. a grass-cutting blade or shredder blade) must be checked in case they need sharpening. If they are bent or broken, they must be replaced.
Maintenance checklist
After completing your maintenance work, clean the grass trimmer guard and cutting tool with a damp cloth or a soft brush; for very stubborn dirt you can use an all-purpose cleaner. As you clean, check that the components are mounted securely and correctly.
As an ongoing maintenance routine, you should check the condition of your grass trimmer carefully all over before any use and every time the tank is filled. It must be cleaned each time it is used – for tools in professional use, that may mean cleaning on a daily basis.
The control handle must be checked regularly to ensure it is working properly. Check the off button can be pressed and the throttle and lockout triggers move smoothly.
Clean the air filter as required during your maintenance checks, and in particular in the event of any malfunction. If the air filter is damaged, it needs to be replaced.
The pickup body should be replaced at least once a year. If your grass trimmer is not working properly, it is advisable to have the pickup body checked: contact your trusted STIHL dealer for this essential maintenance.
Clean the fuel tank as required. Ensure the tank lid is leak-tight.
Check the carburettor idle setting each time before starting work, as well as after refilling the fuel tank. The cutting tool should not rotate when the grass trimmer is set to idle; if it does, adjust the carburettor according to your operating instructions.
As a regular maintenance and servicing step, we recommend replacing the spark plug after 100 hours of use.
Inspect the cold air intake after using the tool and clean it as necessary.
Apart from adjustment screws, all accessible screws and nuts should be checked and re-tightened as needed.
Perform a maintenance check of the anti-vibration elements before starting work with your grass trimmer, or if a fault occurs. If the anti-vibration elements are damaged, they must be replaced by a STIHL dealer.
The cutting tool must be inspected before starting work and each time after refuelling. Always check that it is fitted securely, and replace it straight away if it is damaged.
If you have a metal cutting tool always ensure it is suitably sharp before you use your grass trimmer.
Your gearbox lubrication needs a maintenance check after 25 hours of use, or if something goes wrong with your grass trimmer. Open and inspect the gearbox above the mowing head: if you can’t see any grease, top it up with a suitable product. Frequent maintenance in this area will stand you in good stead.
Replace any damaged safety stickers.
Why won’t my brushcutter or grass trimmer start?
This may be because of the petrol mixture – you should not be using fuel that is over 30 days old. If you’re not sure how long the fuel has been in the tank of your grass trimmer, it’s best to replace it.
Summary: grass trimmer maintenance
- For safe maintenance, always read the operating instructions first.
- Make sure you use the right petrol mixture in your grass trimmer.
- Always check the grass trimmer cutting tool before you start work.
- Always clean the grass trimmer after finishing work.
- Replace the fuel mixture as required.
