DIY trimmer repair

In detail: do-it-yourself trimmer repair from a real master for the site my.housecope.com.

An indispensable tool for a modern summer resident or owner of a private house is a petrol cutter, which allows you to effectively and efficiently put the adjacent territory in order. The period of active use of brushcutters is in late spring until October. Modern units are equipped with powerful and durable internal combustion engines, reinforced transmission and main components. Despite this, physical wear, manufacturing defects or improper operation lead to failure of the trimmer. In order to repair the trimmer with your own hands, you must have at least basic knowledge in the field of technology and little experience in repairing it.

The main unit of any gasoline tool is the internal combustion engine (ICE), which, through various methods, transmits the torque to the actuator. In a modern petrol cutter, a duralumin rod (pipe) is used as a transmission element between the engine and the trimmer head, inside which the drive shaft is located.

Thanks to the high-revving engine, the line speed can reach 13 thousand revolutions per minute, depending on the manufacturer of the scythe. In order to exclude mechanical and thermal damage to the gearbox, a special hole is provided in its housing for the introduction of grease in the form of ointments. To make the headset easier for the owner during long-term work, all brushcutter models are equipped with a durable shoulder strap.

Regardless of the manufacturer, almost every model comes with a line and steel knives.

Video (click to play).

The cross-section of PVC trimmer line can vary from 1.5mm to 3.0mm.

Made of durable polymer, it is subject to intense wear and tear during mowing and, as a result, breakage. Therefore, from time to time it is necessary to check the presence of a fishing line in the head and, if necessary, replace it. It is recommended that you purchase an extra bobbin to quickly replace it with a spool with no line.

ICE trimmers on the market today are equipped with a D-shaped, U-shaped or T-shaped handle, where the main controls of the unit are located. For example, in a braid with a U-shaped grip, the throttle key and stop / start toggle switch are located on the right grip. In the D-shaped version of the handle, the throttle control button is located directly on the rod.

Due to the presence of many components and parts, repairing a trimmer with your own hands means eliminating breakdowns that prevent its normal operation. It should be noted the most basic malfunctions of gasoline streamers:

  1. The trimmer motor is not picking up speed;
  2. Breakdown of the cylinder-piston group (CPG);
  3. Ignition malfunctions;
  4. There is no connection between the internal combustion engine and the trimmer head;
  5. Mechanical knocking during unit operation.
  6. Repair of the central piston group petrol cutters

The main unit of any internal combustion engine is a cylinder-piston group (CPG), which can fail due to wear of parts of parts or poor quality of the fuel mixture.

Lubrication of rubbing units in a petrol cutter is carried out by adding a certain proportion of oil to gasoline. This process can be disrupted due to old oil precipitating out. In this situation, when the trimmer is started, the motor overheats and in a matter of minutes the most expensive breakdown occurs. To eliminate the malfunction that has arisen, a complete replacement of the CPG will be required, namely: the piston, oil seals, cylinder and piston rings.If you are not an ICE repair technician and do not have experience working with technicians, then you will hardly be able to fix the engine without the help of a specialist. Details on the stages of piston trimmer repair can be found here.

If the ignition of the petrol mowers fails, the spark on the candle disappears and, as a result, the fuel mixture does not ignite.

Spit spark plug design

In this situation, it is quite important not to rush to replace the coil, since the cause of the breakdown may lie in the lack of contact in the switch on the control handle.

An important point when troubleshooting the trimmer ignition will be the diagnostics of the section, where the distance between the side and center electrodes should be 0.5-0.7 mm. In addition, it is necessary to pay attention to the steel O-ring on the spark plug, the loss of integrity or deformation of which can lead to etching of air from the combustion chamber and, as a result, reduce the power of the streamer.

Ignition flywheel with coil

If the replacement of the check of the electrical circuit, the spark plug and its contacts did not give positive results, then you should pay attention to the trimmer ignition module, namely the clearance with the flywheel. Regardless of the design features and the manufacturer of the brushcutter, the distance between the ignition coil and the flywheel should be no more and no less than 0.2 mm. To restore the optimal value of the gap, you will need to loosen the coil mounting bolts and set the trimmer ignition with a special measuring probe.

A clear sign of a malfunction of the engine power system is the absence of traces of the fuel mixture on the spark plug electrodes, which may be associated with the following defects:

Trimmer Fuel System Components

  • due to a clogged hole in the gas tank, a vacuum is created, which prevents the normal flow of gasoline into the carburetor;
  • due to the poor quality of the fuel and the ingress of foreign particles, the fuel filter installed in the tank is clogged;
  • non-flow of the mixture into the combustion chamber as a result of a clogged carburetor.

You can quickly determine the cause of the malfunction by dismantling the fuel hose leading to the carburetor. If the fuel mixture flows out in a thin stream, then you should pay attention to the carburetor. If there is no jet, it is necessary to clean the breather with a thin needle (a small hole in the gas tank cap) or replace the fuel filter.

If fuel enters the carburetor, it must be cleaned or adjusted. Adjusting the carburetor trimmer means restoring optimal fuel mix.

Trimmer carburetor with adjustment screws

To do this, pay attention to three adjusting screws: maximum speed (H), minimum (L) and idle speed (LA). To start the adjustment, you need to fully tighten the screws H and L and loosen one turn each. Then we start the braid and let it warm up for 10 minutes to adjust the power system in operating mode. After warming up the internal combustion engine, press the gas supply button until it stops (12,000 rpm). We restore the idling mode by unscrewing the screw LA. As soon as the trimmer head starts rotating, tighten the screw until it stops.

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One of the common faults of the petrol mowers is the incorrect operation of the internal combustion engine, namely the drop in power with increasing speed (the scythe stalls).

The reason for this is that the exhaust system is clogged with burnt oil particles. Often manufacturers make mufflers prefabricated and cleaning is quite simple. If the design of the spark arrester is non-separable, then it must be placed in water with detergents, and then dried with an ordinary or industrial hair dryer. Frequent clogging of the exhaust system indicates non-observance of the proportions of oil and gasoline.

Image - DIY trimmer repair

Any complex technical equipment has a limited working life. And with an increase in the intensity of its operation, the risk of its failure increases. However, it is within the power of each owner to reduce the number of such emergencies if the rules for use and maintenance recommended by the manufacturer are followed exactly. In any case, you should be prepared for the fact that at a certain period, malfunctions in the operation of the device will still arise. Malfunctions that can occur in the trimmer operation can be of a different nature. However, in some cases, it is quite possible to repair the trimmer on your own.

Image - DIY trimmer repair

Equipment that operates on mains differs from similar devices that provide a built-in power drive in that it has a simpler design. The main components of a trimmer are:
  • mechanical part that transmits torque to the trimmer head;
  • electric motor;
  • power cable.

In this case, all the problems that may arise with this equipment can be presented in the form of the following groups.

Main function when using the device assigned to the trimmer head, in which the cutting surface is made of fishing line. In most cases, the device fails due to problems with its supply.

  • Image - DIY trimmer repairIn case of using up the supply of fishing line, it is necessary, following the instructions of the instructions, to wind a new one.
  • Line entanglement may be one reason for work stoppages. In a similar situation you need to unwind it and insert a new bobbin if it shows signs of damage.
  • Also, the trimmer may fail due to stuck nylon thread, which may be associated with overheating of the device during its long-term use. This problem is solved by rewinding the line.
  • Malfunctions can be directly related to the coil: for example, the bottom of it may fall off. Repair in this case will be reduced to replacing it or creating a new bottom with your own hands. Having chosen the last option, it is necessary to prepare a piece of PCB or a bolt with a nut.
  • In some cases, the coil may not show signs of damage, the motor may also be fine, but the head does not rotate. In a similar situation, you should look at the drive shaft. If the fear of its breakage is confirmed, then the device must be handed over to a service center.

If the failure of the gasoline trimmer is associated with malfunctions in the mechanical part, then the repair technology will for the most part repeat the work carried out in relation to electric models.

Image - DIY trimmer repair

To carry out repairs to electric trimmers, you must prepare the appropriate tools:
  • indicator screwdriver;
  • multimeter;
  • blowtorch.

It is rather difficult to find out by visual inspection what caused the malfunction; in most cases, only the most obvious malfunctions can be identified by eye.

Regardless of the nature of the malfunction, this in any case leads to the termination of the engine.