Basic maintenance should be part of your routine when it comes to your petrol machines. You should be keeping an eye out for a blunt saw chain, for example, and making sure that you sharpen it as needed.
And we’ve all seen the state of kombi cans after a while, so we recommend that you always try to keep a clean fuel tank, keep the dirt off the top of your kombi can to prevent it going into the fuel tank, and give it a wipe down or spray at the end of the day as part of your regular maintenance. You’d be surprised how much gunk can get into the fuel system, even when the cap is only off for a few seconds – and some (most) of this is usually down to a dirty can!
This is particularly important as any dirt that does get into the fuel tank can cause premature wear to solenoids. Sometimes when a saw is hot, it won’t restart, or the machine may not idle and a worn solenoid may well be the cause. This is because a leaking solenoid valve lets too much fuel into the engine.
The solenoid replaces the manually adjusted screws on the carburettor so the opening and closing of the fuel solenoid varies the amount of fuel going into the machine. This is controlled by the M-Tronic module, which acts as the brain of the machine. You can find out more about our M-Tronic technology here.
If you think the solenoid needs replacing, it is fairly simple to do yourselves. Just follow these simple steps in our guide to changing a solenoid valve:
Step 1: Removing the old valve
- Take out the screw (25).
- Remove the holder (24).
- Pull out the solenoid valve (19).
Thoroughly clean the exterior of the carburettor.
Step 2: Installing the new valve
Do not hold the solenoid valve (19) near the collar (arrow) since the sealing faces may otherwise be damaged.
Hold the solenoid valve above the collar.
- Coat the solenoid valve below the collar with press fluid.
- Push in the solenoid valve (19) so that it is between the two guides (arrows).
- Press home the solenoid valve as far as stop.
- Fit the retainer (24) so that the nib engages the bore (arrows).
- Insert and tighten down the screw (25).
At all times, it is very important to make sure that no dust or dirt gets into the bore of the valve seat.
Don’t forget – you should always do an M-Tronic reset on the saw after changing a carb or solenoid too.
If a solenoid valve continues to fail, we suggest checking the fuel lines or the fuel filter. And if a replacement solenoid valve is not the cure to your machine’s problems, it may be a carburettor maintenance issue, such as wear to diaphragms. In which case, your local STIHL dealer will be able to help so pop in and let them have a look.