Repair and maintenance of lawn mowers

Lawn mowers are a handy technique that allows you to keep grass cover in a tidy condition in the country, in the garden, in the park. Thanks to their use, lawns take on an attractive appearance with minimal effort and time. Popular petrol and electrical devices, pushed into the background mechanical models mowers.

With proper operation, the equipment can work for more than one year without damage. But over time, parts wear out or an unexpected accident may occur, causing the unit to fail. If the technique not warranty, it is not necessary to contact the service center for help from specialists. Repair and maintenance of lawnmowers can be done at home. This is due to the fact that many faults do not relate to serious damage, they can be fairly easily resolved on their own.

The main malfunctions of electric and gasoline lawn mowers

Despite the variety of models and manufacturers of lawn mowers, gasoline and electric equipment has similar structural components. The difference lies in the types of engines installed and the associated maintenance systems. Equipment malfunctions are conventionally divided into 2 groups:

• mechanical;
• associated with the drive part.

Mechanical breakdowns of the models with petrol and electric motors are almost the same, but failure to operate the driving part of the lawn mower can be caused by problems with different parts.

Mechanical problems

The mechanical system of lawn mowers with different drives consists of the following structural elements and components:

• knife (rotary or cylindrical type) or fishing line;
• transmission mechanism;
• grass catcher and grass ejection devices;
• wheels, handles and body.

Failure of the cutting element

The most frequently damaged (for example, bend) or blunt knives, ends fishing line. This is easily detected with a simple visual inspection.

The fact that the cutting attachments have become blunt is indicated by the uneven cutting of grass stalks during mowing by a lawn mower.

With time mount knives may weaken. Their balancing during rotation is disturbed, and vibration, whistling, rattling appears. If the knives are damaged, then during operation the mechanism will begin to make in addition uncontrollable, sudden, sharp movements. To troubleshoot this kind of cutting elements expose in the desired position, replace with new ones or repair. If possible, sharpen the blades.

Sounds and vibrations when working

Unusual sounds, vibration, rattling appear during the operation of the unit, when the attachments of its structural elements are weakened: the housing, the engine. These phenomena are more common in gasoline models, because their motor fluctuates more during operation than an electric motor. To eliminate these phenomena check all connections, tightening the bolts, if necessary. It happens that the whistle during the operation of the unit occurs due to getting inside foreign object, which blocks in the aerator roller. In this case, it is enough just to get it to stop the sound.

Cutting tips do not rotate

Often when mowing high grass or hard grass stand, the cutting heads no longer rotate due to grass driving. This problem in most cases (if it did not lead to more significant negative consequences) is easy to solve with your own hands simply by picking out the stems of the plants.

Breakdown of structural parts

Damage to the wheels, handles and body rarely occur. If they are significant, then change these structural elements.The methods of repair, if possible, in each case depend on the material of the broken parts - they can be plastic, aluminum, steel.

Belt break

During prolonged use, the mower wears, stretches, and then breaks the belt. At the same time, the gasoline engine of the device works, and the knives do not rotate. Self-propelled models may also break off. wheel drive belt: then they stop and do not go. Sometimes the clutch cable simply stretches and needs to be adjusted.

Frequent problems with the drive system

The drive unit in electric and gasoline-powered mechanisms is arranged differently. In this case, the engine is its main element. Failures associated with the motor, are accompanied by the following malfunctions:

• lawn mower stops winding up;
• after launch, the equipment almost immediately stalls;
• during operation, engine power does not fully develop;
• excessive vibrations during operation.

As a result of a collision with a stone, a stump or another hard obstacle, the shaft on which the knife is installed, as well as its associated nodes, can be damaged. Then more radical repairs will be needed.

In most cases, you will need to contact a service center for assistance.

On petrol mowers install two-stroke or four-stroke internal combustion engineshaving a different design. For this reason, problems with the motor can be caused by a breakdown of identical parts, as well as different ones. Regardless of the manufacturer, lawn mower repairs with the same type of drive installed are produced in the same way.

Motor Diagnostic Tools

To identify problems with lawn mowers with a different type of drive and their elimination you will need the following devices and tools:

• indicator screwdriver;
• multimeter or tester with voltage indication;
• screwdrivers;
• wrenches or hex wrenches (depending on the fasteners used in the assembly of equipment);
• pliers;
• clippers;
• knife;
• hammer.

From materials may need insulation tape and details found during the inspection.

Causes of lawnmower engine breakdowns are related to the following factors:

• overheating or overloading the motor;
• poor contacts or breaks in the electrical circuit (for electrical models);
• violation of the supply of fuel or oil (in gasoline units).

Therefore, it is necessary to periodically, focusing on the recommendations outlined in the operating instructions, make stops while working and constantly clean the equipment from herbal residues.

For internal combustion engines, you should use a suitable oil and the specified brand of gasoline in the passport.

Identification and elimination of problems with the operation of electric motors

To find out the reason why the electric lawn mower does not start, stops after switching on or during operation, the following measures are taken sequentially.

1. Check supply voltage on its compliance with the value given in the passport of the equipment. If it is higher or lower than normal, you will need to use a stabilizer or stop working for a while.
2. Visually inspect cord with plug (and a fuse in it) for the presence of mechanical damage, and when they are detected, they change the cable or connect it and insulate it again.
3. Then go to power button: it is disconnected and checked using special tools.
4. Inspect for the presence of swelling or oxidation capacitor.
5. After go to check electric motor lawn mowers: visually check the presence of burnt sections of the winding or with the help of the device its integrity.

After detecting a breakdown at any stage and its elimination, check the operation of the equipment as a whole. Instead of a damaged plug, they uniquely install a new one. The integrity of the power cord and the performance of the on / off button can be easily determined using a multimeter or a tester (even an indicator screwdriver).

Go directly to checking phase shifting capacitor It is recommended for the following signs in the operation of the unit:

• at the time of supply voltage, the electric motor is twitching;
• the electric motor overheats at idle or at a low level of load;
• a non-characteristic buzz emanates from the motor;
• electric motor is not gaining momentum.

A failed capacitor is replaced with a new part of the corresponding capacity.

Visual signs that electric motor burned out, is the blackening of its windings, the melting of their insulation, the fusion of copper. When such phenomena are present, you will need to replace the electric motor yourself or turn to professionals.If there are no external signs, and the multimeter shows the presence of a gap in the winding, then you will also need to change the motor.

The collector models of electric motors immediately check brushes: they are cleaned with emery paper or changed.

With many years of operation, mowers can wear brake pads electric motor. In this case, you need to disassemble the motor and remove the lining.

Starting to search for the causes of failure, it should be borne in mind that technology equipped with electric motors, problems with starting and operating the motor is mainly associated with poor contacts in the electrical circuit or violation of the integrity of the wiring. Much less often the starting button fails, the phase-shifting capacitor or the electric motor (due to overload or overheating). A number of models of lawn mowers equipped with thermal motor protection - it can work, while the mechanism will not turn on. To eliminate the problem, it is enough to close the circuit.

All working operations with electric models of lawn mowers are recommended to be carried out with their disconnection from the network in order not to get an electric shock.When repairing an electric motor and a control system with your own hands, you must have a basic understanding of electrical engineering in order to properly perform the work.

Causes of gasoline engine failures

Petrol (especially four-stroke) internal combustion engines are designed to work in areas with a slope of not more than 15 degrees. Short-term 30 degree distortions are allowed. With large slopes motor may stall. Some models of mowers have a throttle lever: you need to set the ignition on the lawn mower to a maximum before working.

Repairing an internal combustion engine with your own hands is considered a more difficult task than an electric motor. This is due to the greater complexity of its design. You need to know the device two-stroke and four-stroke engines, their design features.

Starting repair works, it is necessary to check the course of a rope of a bracket (lever) of safety. You may need to adjust it.

Problems with the fuel mixture

The simplest causes of problems with a gasoline unit is the lack of fuel. Its availability is not difficult to verify.It should also look at the four-stroke engine models condition and oil level. If it is contaminated or it is small, then you need to fill in a new liquid, drain the old one before that.

During continuous operation of the mower, the carburetor is contaminated by the products of combustion of fuel or due to the poor quality of the gasoline poured. As a result swim engine speed. You can clean the carburetor assembly yourself. To do this, it will need to disassemble and rinse with a special tool. You can try to initially blow through the air to remove clogs.

It should be remembered that before installing in place must be made to adjust the carburetor. For the motor to work well, it needs to be properly configured.

The fuel hose is also clogged with poor quality gasoline. When it does not arrive, the saloon is cleaned with a needle and replaced with a fuel filter. When clogging the air filter engine power drops. In such cases, the filter element must be cleaned or replaced.

Starter cord break

Often, problems with starting are caused by a broken starter cord.In the simplest version, repairing a starter consists in tying a rope in a knot. In more complex situations, you will need to disassemble the entire assembly and change the cord.

Spark plug malfunction

If the gasoline engine does not start at all or immediately stalls, you should check the spark plug. It should produce a spark, visible even in daylight. For this, it is twisted and inspected. If there is no spark, then replace the part. In appearance of the candle you can diagnose damage:

• if it is dry, this indicates a problem in the fuel supply system;
• when the candle is wet, the carburetor malfunctions cause malfunction;
• in the presence of black soot on the candle, it is cleaned or replaced with a new one.

Other breakdowns

Poor gasoline engine works with partial wear or burning pistons. For repair you will need to disassemble the engine and put the whole parts. May also occur mechanical damage, for example, jamming of the crankshaft or piston, the appearance of cracks in the carburetor or motor housing. In such situations, you will need to install new parts.

Serious repairs to gasoline engines require professional knowledge andskills. If they are absent, it is better to contact the service center to specialists.

Cutter Diagnosis

With constant use of the lawn mower, its cutting attachment becomes dull with time. The following indications are indicative of this:

• grass cover is unevenly mown;
• plants are uprooted;
• increases the time spent on work;
• increases fuel consumption or electricity.

When these phenomena occur, the cutting part needs to be inspected and, if necessary, removed, after having previously cleared the grass clippings. If there is cracks in metal or deformations that do not allow balancing of the blades, then the cutting attachment needs to be replaced. When the wear parts are insignificant, then sharpening knives. It can be relatively easily produced at home with your own hands.

To remove the knife rotary or cylindrical type, and then sharpen it or install a new one, perform the following preparatory activities:

• drain the oil;
• electric lawn mowers are disconnected from the mains, and on gasoline units they press a button that blocks their inclusion;
• from the units working on gasoline, they drain fuel or fully produce it, unscrew the spark plug;
• put the mechanism on the support, allowing to get free access to the cutting nozzle.

The latter is only necessary if on the instrument installed internal combustion engine. You can also tilt this equipment in the direction of the handles by removing the collection box from it. Models with an electric motor can be repaired in any convenient position.

If there are no special means to block the shaft, then you need to do it in another appropriate way.

Before work, it is recommended that you wear tight gloves to protect your hands from possible cuts on the blades.

Removing and installing knife

Cutting nozzles rotary type most models are attached to the drive shaft with a bolt. It is located in the center of the part. Replacing the knife on the lawnmower in this case is as follows:

• in the presence of grass fragments clean them with a broom or brush;
• unscrew the fastening bolt with a wrench of a suitable size (usually the number 19);
• put the knife (the same length as the one taken) in the correct position, tightening the fastening bolt with the key with the effort required by the instructions;
• check the uniformity of rotation of the nozzle, twisting it with your hand: the distance from the deck should always be the same;
• put the unit in working position.

When the bolt fails to unscrew the key, you can gently tap it with a hammer. If this does not help, then you should pour the fasteners with kerosene or brake fluid. Use extra levers with a key with caution, because you can break the top of the bolt. Heating the fastener also contributes to its unwinding.

Meet rotary-type knives with two short nozzles. In this case, the replacement work is performed in the same way. Change cylindrical knife can be the same way. The difference lies in the design features of attachment of the nozzle of this type.

It is necessary to remove the cutting attachment carefully so as not to lose the details. At the same time, its position should be remembered in order to place the new blades correctly.

Sharpening blades at home

You can sharpen the blades of the lawn mower yourself using the following tools and accessories:

• Bulgarians;
• grinding machine;
• file;
• sandpaper;
• an obelka (bar) or an abrasive stone.

Before sharpening should wear gloves. If the work will be performed on a grinding machine or using an angle grinder, then you need to use a mask or glasses to protect your eyes from abrasive or metal particles.

Before sharpening a knife, it is examined for the presence of deformations and the degree of wear. Existing bends are leveled on an anvil or a piece of rails with a hammer.

When working on the grinding machine The cutting attachment is brought to the rotating circle and the blade is pressed against the sandpaper under a certain inclination. To align the edge initially put a coarse-grained circle. Lapping and grinding perform on the fine-grained circle. If possible, then grind the item with a felt wheel - it is intended for polishing. Some machines are equipped with devices that allow to fix the workpiece - it facilitates the sharpening process.

Sharpen the blades of knives using hand tools or grinders it is recommended, previously having clamped a nozzle in a metalwork vice. If the cutting edge of the working nozzle is badly damaged, then it can be cut, but only immediately from both sides.In all cases, a strong effort should not be applied. As a result, the blades should be sharpened at an angle of 30 degrees.

After turning check blade balancing. For this, a screwdriver is inserted into the bolt hole, for example. Then raise it to a vertical position: the knife must remain in the horizontal plane. When imbalance occurs, the imbalance should be restored. This is done by simply grinding off metal from the heavier (outweighed) side of the nozzle. The removal of the layers of material is carried out little by little, checking the balance.

Replacing the line in the lawn mower

In addition to knives on the lawn mower can be installed fishing line. This nozzle is a coil on which is wound nylon thread. Mowing coils come in two varieties:

• with 1 bar;
• with two protruding ends of the nylon thread.

The structure of the nozzle is simple: in the coil there are two departments, between them there is a partition, in which there is a notch. The thread is wound on these tracks. For its output from the coil there are special holes.

On different models of lawn mowers, cutting tips are used with a different thickness of fishing line.This parameter is in the range of 1.2-4 mm.

In addition, the polyethylene thread varies in sectional shape. This defines the scope of use (purpose) of the material. According to these criteria, the fishing line can be of various types:

• the round, which is the most durable variety used for cutting grass cover;
• figured, used when mowing plants with soft stems;
• twisted, suitable only for thin herbage.

There is a cord professional type. But this variety is not suitable for use on all models of equipment.

The nozzle itself is rarely damaged, it only wears out and ends with a nylon thread. To resume work, you need to re-wind the line. It is worth buying the thread that is suitable for the coil installed on the lawn mower.

The procedure for the replacement of fishing line in the coil with one barb

To change the line to the coil with one issued tendril, proceed as follows:

• turn off the lawnmower, electrical disconnecting from the network;
• remove the cutting attachment, pre-locking the shaft from turning, for example, using a screwdriver;
• disassemble the case, usually removing its cover by pressing the latches;
• lay out carefully all the details;
• cut from two to four meters of fishing line with a diameter specified in the instructions for the attachment used;
• fold the piece in half to divide it into two identical pieces;
• one end of the cord is threaded into the ear inside the coil;
• wind the thread counterclockwise (in the direction opposite to the rotation of the nozzle during operation);
• leave a small end of the thread, which is thrown out through the hole, having previously been fixed in a special slot so that it does not unwind;
• collect coil;
• set the nozzle on the lawn mower.

When cutting is installed nozzle with automatic or semi-automatic feed cord, inside it has a spring. Therefore, when disassembling the case, it is necessary to ensure that it does not fly out and not get lost.

The groove locking the line may be missing. In this case, it is held by the hand during the assembly of the nozzle so that it does not unwind.

Replacing fishing line in other types of reels

To properly reel the line in the reel with two protruding ends of the cordneed to disassemble it. Inside are two notches. At the same time, the ends of the fishing line are laid out separately according to these grooves.The winding is also performed in the direction opposite to the rotation of the nozzle.

There are models of coils having a different design. In such cases, it is often not necessary to disassemble the nozzle to insert the cord. Thread is inserted in a special through eyeinside the coil. The line is wound up due to pressing a button. It is located directly on the body of the cutting nozzle and is designed so that when the cord is worn out, it can release its new ends without disassembling the coils.

It is recommended to carry out work on the replacement of fishing line on gasoline mowers with the switch-on button locked.

Before you twist the line, it can be pre-soaked for a while in water - this will increase the strength and elasticity of the inserted thread. Winding metal cables is prohibited. The cord should correspond to the diameter specified in the instruction.

It is necessary to start repair of lawn-mowers only after preliminary acquaintance with the instruction for their operation. It discusses the design of the model and the rules for its use. To minimize the likelihood of damage, you must follow regular maintenance requirements.You need to use only high-quality fuels and lubricants.

Before starting mowing grass, it is recommended to inspect the pre-treated area for the presence of stones, stumps and other obstacles. This will help avoid accidental collisions and unforeseen accidents. Also note that a lawnmower is recommended work with dry grass, because it slowly clogs knives and other parts of the mechanism.