To keep the areas adjacent to our garden clean and tidy, an extremely useful and effective tool is the brush cutter. However, it may happen that when needed, the tool does not start, especially if it is not used often.
So let's try to summarize what to do when our brushcutter does not want to start: there are in fact some things that it is good to check to ensure a correct engine start and could solve the problem without going to a mechanic.
Speaking of starting the engine, we are referring to brushcutters with petrol engines, since battery-powered brushcutters or wire-powered electric ones have fewer starting problems.
Below you will find summarized the main elements to check to know if a brushcutter is in the right conditions to start and work correctly, first of all, however, it must be remembered that to prevent the misfire it is necessary to periodically carry out maintenance on the vehicle and keep it clean in every its part.
Check fuel level and stop button
If we are unable to start our brushcutter, we must first check two apparently trivial things, but which can always happen to be forgotten.
The first check that needs to be done is that there is a quantity of fuel in the tank sufficient to allow the machine to be powered. If there is no fuel mixture (or petrol) it is easy to understand why the tool does not work and the problem can be solved with a full tank.
The second verification is that the shutdown switch is in the "on" position and has not remained set to "stop", this lever presides over the electrical circuit and to ensure starting of the brush cutter must be "on", in order to allow the spark plug to be powered. If our brushcutter has visible i cables that from the command go to the engine we must also make sure that they are not interrupted or peeled.
The pull starter
Most of the brushcutters with petrol engines lights up by pulling a string, the jerk that is given manually in this way is what sets the piston in motion and therefore the crankshaft which, thanks to the alternator, produces current to power the spark plug. This in turn produces the spark that starts the combustion, starting the brushcutter. The cable is wound on a reel equipped with a spring that automatically rewinds it inside the machine after each tear.
If you feel the extremely soft cord and does not go back into place after being pulled, probably the spring has broken. If you feel it instead excessively hard and it is not rewound after being pulled, the lever system that connects the spool to the crankshaft may have broken. By disassembling it is possible to change or rewind the spring, even if it is an operation that requires patience, the right tools and excellent dexterity. In general, although it is a minor inconvenience, we recommend that you contact your trusted mechanic due to the difficulty of reassembly.
Air lever and fuel pump
Having made sure that the tank is full, the key to ON and the line in place may not be enough to start the brushcutter. To facilitate ignition, we have two other very simple tools available: the choke lever and the fuel pump, the latter is not present in all models.
There air lever it is a lever that controls the access of air into the carburetion, in some models it is a button, in others an open / closed selector. When you need to start the machine cold it is useful to close the air. In fact, each internal combustion engine has a carburation that regulates the air / fuel ratio and allows it to function perfectly.
However, it happens that this adjustment is not suitable for the first start-up: starting with a cold engine is facilitated by a more fatty carburetion. For this reason, on the engine, near the carburetor, we can find a lever or a button that allows us to make the mixture richer.
Make sure you have activated this control only if you are starting the engine from cold, otherwise you risk flooding the engine. Even if you have already tried starting many times with the command activated, it is advisable to wait a few minutes before trying again.
Many brushcutter models also have one pump to fill the carburettor with fuel, to be operated manually by pressing with your finger. Before cold starting it is good to pump a dozen times, another precaution that facilitates the starting of the machine.
To further simplify starting in all conditions on some brushcutters it is possible to lock the throttle control in the slightly accelerated position. Generally this can be done by fully pressing the accelerator control and at the same time a button near it.
This forces the tool to start accelerating: be careful because as soon as the engine starts, the head will start rotating at good speed.
Check and clean the spark plug
The spark plug is the element that provides the spark necessary to trigger the combustion of the fuel. If the brushcutter does not start it is possible that the reason is in the dirty or non-functioning spark plug. In the life cycle of a 2-stroke engine, especially if it is fueled with a common mixture of petrol and oil, it is normal for the spark plug to become covered with carbon residues over time, which hinder its timely operation.
For this reason, if our brushcutter does not want to leave, it is advisable to open the cover on the head of the engine that hides the spark plug and unscrew it with the supplied key. If it is covered with sludge it is necessary to clean it with a metal brush and check the correct distance between the electrodes. If the spark plug is wet it means that the engine is flooded: we can simply dry it and clean it if necessary.
Once this has been done, we can check its operation by connecting it to the power cable and placing it in contact with a metal part of the motor (generally on the head, near its hole). Pulling the starter cord with the stop button in the "on" position we should see a series of sparks in rapid succession between the spark plug electrodes. If this does not happen, the spark plug must be replaced. Always remember that the spark plug works with electric current: to do this check it is recommended not to touch the spark plug directly but to hold it through the rubber cap of the power cable, in order not to get a shock.
Check the air vent
Working in a dusty environment, with fragments of grass splashing everywhere, it is possible that some of this material will eventually settle in the ravines of the engine. When the dirt comes to occlude the tank vent it does not allow air to enter to occupy the space left empty by the gasoline sucked in by the engine. When there are problems with the brushcutter it is always useful to check that the vent is free, usually you can find it on the cap or it can be made up of a tube that protrudes from the tank with a filter at its end.
Check the fuel filter
Similarly, it can happen that over time the tank filter has become filled with impurities. This filter is used to stop dirt particles that may be present in the fuel, or that accidentally end up inside the tank. When the filter is clogged, it does not allow a good flow of fuel to the engine and therefore affects its operation.
To remedy the problem and allow the ignition of our tool with the help of a piece of wire with a curved end, we can extract the supply hose through the filler hole of the tank and check that the filter at its end is not blocked.
If the brushcutter still does not start
If you have checked everything we have explained in this article and your brushcutter still insists on not starting, all you have to do is contact a mechanic, or in any case someone who has a good knowledge of the operation of internal combustion engines. If the brushcutter is under warranty, it is advisable to take it to those who sold it or in any case to a workshop authorized by the brand, in order to possibly enforce this warranty.