Lawn Mower Repair: DIY Electric Mower Engine Repair. What Is The Reason For The Mower Not Picking Up Speed? Why Is There No Spark?

2024 Author: Beatrice Philips | [email protected]. Last modified: 2023-12-16 05:33

Maintenance and repair of the lawn mower can be done by hand and at home. Naturally, the implementation of such work has its own characteristics. It is worth considering the need for the availability of appropriate knowledge, skills and tools.

Frequent malfunctions

Regardless of the operating conditions, the owners of lawn mowers sooner or later have to deal with the fact that they do not turn on at all or do not work normally.

Timely identification and effective troubleshooting is the key to the longest possible service life of the equipment. The "symptoms" of the most common breakdowns include:

• the appearance of extraneous sounds in the deck area;
• very noticeable vibration at the moment the knife is turned on;
• the appearance of a whistle during the operation of the lawn mower;
• significant deterioration in the quality of mowing.

In addition, in situations with gas mowers, one often has to deal with the fact that the device does not start well or does not gain momentum. The list of reasons for such malfunctions is quite wide.

At the same time, their timely identification and the presence of certain knowledge allow you to repair the devices on your own with minimal costs.

Identifying the causes of breakdown

Features of diagnostics and subsequent repairs are determined taking into account the type of lawn mower. So, in situations with electrical models, it should be borne in mind that their operation depends on the state of the electrical equipment. The first symptom of malfunctions is when the equipment does not turn on when connected to the network. In such a situation, the following actions must be taken to identify breakdowns.

1. Check the presence of voltage at the connection point with a measuring device. It is about the operability of the electrical outlet.
2. Check the integrity of the electrical cable.
3. Assess the performance of the lawn mower button.

It is best to perform such checks using a tester. In some cases, the cable and the power button are replaced with obviously working ones. If the listed manipulations did not give a positive result, then we can talk about a malfunction of the electric motor.

In such situations, the most rational solution would be to contact a service center.

Today, the most common are gas mowers. Faced with their malfunctions, the owners, as a rule, use the services of specialists. However, you should first determine the nature of the breakdown. To do this, it is recommended to pay attention to the state of the "pain points" of the described technique, namely:

• spark plugs (if there is no spark);
• air and fuel filters;
• operability and tuning of the carburetor;
• muffler.

Engine starting problems can occur for several reasons. The main ones are the absence of spark and fuel supply. Determining the source of the trouble can be quite simple. The presence of loose carbon deposits on the spark plug indicates the poor quality of the fuel mixture used and the need to replace the air filter.

In such situations, unburned fuel particles settle on the contacts, causing a short.

A dry and clean plug can be an indicator that an air lock has formed in the system, preventing the supply of fuel. One of the reasons is a clogged carburetor jet. However, first of all, the fuel line is purged and the filter element replaced.

The third possible option is a clean and damp candle. In such situations, fuel comes in, but there is no spark. Most often, this happens for the following reasons:

• failure of the candle;
• breakdown of a high voltage wire;
• switch malfunction.

The listed malfunctions can be eliminated by an elementary replacement of the indicated elements. It should be borne in mind that each of the types of lawn mowers existing today has its own characteristic breakdowns. The appropriate instructions and operating manuals will help to identify them.

How to disassemble the mower?

Repairing a lawn mower is impossible without disassembling its individual units. In this case, it is necessary to take into account the features of the device of a particular model. So, to eliminate shaft malfunctions and lubricate its elements, you will need to disassemble the rod, which includes:

• a drive shaft with square splines or edges at the ends;
• a tube made of aluminum;
• plastic anti-vibration bushing;
• rubber shock absorber, which is a connecting element for the rod and the motor;
• stubborn stand;
• belt;
• steering wheel.

During the disassembly of this unit, all of the above components are dismantled, as well as the gas regulator, the locking device (handle) and the ignition switch. Among other things, you will have to remove the gearbox, which is attached to the bottom of the rod to be dismantled.

It should be borne in mind that this part is not provided for by the design of a number of lightweight models, since they have a curved bar and a flexible cable instead of a shaft.

If in the process of starting the lawn mower, the knives or fishing line move in idle mode, and there is extraneous noise in the front of the power unit, then it is necessary to disassemble the clutch mechanism. This is necessary to diagnose the clutch, spring and pads. This operation includes the following steps:

1. dismantling of the metal stand and cover;
2. unscrewing the cylinder cover and starter cap;
3. removal of screws on the side surface of the shock absorber cover;
4. removing the tube held by the tightening fasteners;
5. parsing the clutch;
6. dismantling the spring to replace the pads.

Often, lawn mower owners have to deal with the failure of the power unit. It is most rational to entrust the disassembly and repair of the engine to specialists. But in some cases, if you have the necessary tool, as well as the appropriate knowledge and skills, such work can be done with your own hands. So, to diagnose the piston system, you will need:

1. loosen the screws to loosen the fastening clamps;
2. remove the crankshaft;
3. dismantle the cylinder head;
4. remove the piston with rings.

Different types of modern lawn mowers have their own design features. The process of disassembling electrical models of the considered equipment includes the following steps:

1. unscrewing the fasteners of the cover;
2. removing the freed part of the housing to provide access to the electric motor, bearings and other elements;
3. detection of melted parts, wire breaks and identification of the characteristic burning smell;
4. disconnecting electrical wiring and all screws;
5. removing the motor;
6. dismantling of bearings and rings on the motor shaft.

During disassembly, using special equipment, the condition of all elements is diagnosed. We are talking here about checking the condition of the power cord, start button, temperature relay. Resistance is determined in parallel.

How to repair?

Special attention should be paid to the work related to the restoration of the operability of the mechanical part of the lawn mower. This refers to both self-propelled and all other modern models. Depending on the situation, it may be necessary to replace the line, rotary knives or cylindrical knives. In some cases it will be necessary to repair the transmission device, handles, wheels or mower body.

The main malfunctions and effective ways to eliminate them can be represented as follows

Damage to the line and cutting devices, which can usually be detected visually. In such situations, the blades are removed, after which they are sharpened or replaced with new ones

Weakening of fasteners of cutting elements, entailing unbalance, the appearance of vibration and extraneous whistling sounds. All this leads to a deterioration in the controllability of technology. The solution will be to adjust the knives and fishing line, as well as tighten all the fasteners

The appearance of knocking and grinding noise caused by loosening the mountings of a gasoline or electric engine. An effective action would be to tighten the corresponding bolts. Similar symptoms may indicate that foreign objects have entered the mechanisms that should be removed

Cutting elements may stall when working in dense growth. This indicates that the mower is not powerful enough and could cause serious damage. In such situations, it is necessary to quickly get rid of the compacted mass. It should be remembered that errors in the choice of power cause the failure of the mechanical components of the device and even the combustion of the power plant

Failed hulls, handles and wheels are restored or changed taking into account the extent of damage

Significant wear and tear of the transmission belts are the result of long-term operation. In such situations, the power unit functions, but the cutting attachments remain stationary. On self-propelled models, the drive belt fails. The only way to repair in such cases is to replace the worn part. Similarly, the breakage of the knife shaft is eliminated after meeting with stumps, stones and other objects.

Quite often, owners of gasoline lawn mowers have to deal with the need to adjust the carburetor. For example, when rotating the cutting elements at idle speed, a reduction in speed is required. Three adjusting screws are used to tune the carburetor with the following functions.

• The right one is responsible for changing the enrichment of the fuel mixture at low revs. The position of this screw is changed first to achieve maximum idle frequency.
• By turning the lower screw to the left and to the right, the engine speed is slowed down and accelerated.
• Using the left adjusting screw, the fuel mixture is changed at high speeds. In this case, we are talking about the final stage of carburetor adjustment.

Repair of electric models of lawn mowers has its own characteristics. It should be borne in mind that the drive system in such situations directly depends on the type of engine installed. Often, during repair work, one has to deal with the failure of a capacitor, as evidenced by the following symptoms:

• the appearance of vibration;
• overheating of the motor at low loads;
• the unit operates primarily at minimum speed;
• a monotonous humming sound is distinctly heard.

If the capacitor and brushes are in good working order, then we can talk about the failure of the electric motor winding. In such cases, you can use the services of experienced specialists or try to fix the unit yourself. The second option involves the following manipulations.

1. Measuring the voltage in the network and checking its compliance with the passport data of the device. If significant deviations are detected, a stabilizer should be used or the operation of such a network should be abandoned.
2. Inspection of the plug and wire in order to identify mechanical damage and check the integrity of the fuses. If damage is found, the damaged elements are replaced with new ones.
3. Dismantling the start button and its diagnostics using specialized devices (tester, indicator, multimeter).
4. Checking the capacitor for oxidation and blistering indicative of malfunctions.
5. Diagnostics of the electric motor in order to identify the burnt sections of the winding and check its integrity.

The power button can be checked without the devices mentioned above. For this, a temporary jumper is installed that closes the corresponding contacts. A running lawnmower, when the plus and minus are connected, will indicate that the button is out of order. The only way out in this situation is to replace the part that is removed from the seat after unscrewing the mounting screws.

If during the inspections significant wear of the brushes was revealed, then they should be replaced . In the course of self-repair, you may encounter problems when replacing old bearings. As a rule, these elements are difficult to remove from the shaft. When dismantling, the risk of damage to the rotor and the seats must be taken into account.

Before replacing a burned out electric motor, you will need to dismantle the fan, rings and bearings.