How to remove the carburetor from a lawn mower. Clogging the adjustment cavity

Gasoline grass trimmer carburetor device

Adjusting the carburetor of a brushcutter is a process that must be mastered for the full operation of the grass trimmer. Grass trimmer. a completely uncomplicated device, which can break only in a few places and require mechanical repair or replacement of the part. Adjusting the float-type brushcutter carburetor device may require knowledge of certain subtleties. The nuances due to the model and the specifics of its functioning will ensure a clear mode of mixing and feeding the fuel mixture.

Champion lawnmower carburetor, how to adjust? This is just the float-type grass trimmer, a common option designed to mix air and fuel in the prescribed proportions. The main problems encountered with the engine are roughly similar to the problems that plague the carburetor in a car:

  • The engine may shut down as soon as you manage to start it. The reason is that the gasoline is not supplied in sufficient quantity. This is called “poor” fuel;
  • Excessive gasoline leads to incomplete combustion, excessive mixture density and uneconomical consumption.

Carburetor Repair

Important! Adjust the carburetor is necessary under different circumstances: a change in temperature, octane number or type of fuel oil, after winter or the end of the running-in period, the load or spontaneous turning of the screws due to strong vibration of the housing. Some owners prefer to adjust the unit before each use to make sure it works properly.

Disassembling the carburetor if necessary to check or repair component parts

The design of different models of carburetors is almost identical, so when working with them, you can use the standard diagram. All elements must be removed carefully, and then laid out in the following order, so that you can successfully place the items in place at the end of the repair work.

  • Remove the top cover. To do this, unscrew the 3 bolts that hold it in place in a circle.
  • The foam tube can also be removed, as it is the upper part of the filter that conducts the air.
  • The fuel hose is removed.
  • The actuator rod is connected directly to it.
  • The cable lug is disconnected.
  • The gasoline hose can be completely removed by pulling it smoothly from the connector.

To finally prepare the carburetor for an overhaul or replacement of the smallest parts, it must be carefully disconnected from the main system. Sometimes it is necessary to disassemble it further. The component parts should be unscrewed carefully and the fasteners should be stacked in groups, as these small parts are easily lost.

How to clean a lawn mower carburetor

The intake needle breaks because of metal particles and stone in the gasoline. As a result, the seat of the intake needle is loose, the fuel mixture leaks. There is too much air in the combustible mixture created by the carburetor, which may cause the engine to “sneeze” during operation. Finally, the needle may stall due to poor-quality gasoline, or the unit has been idle for a long time.

Methods of elimination

A list of upcoming work on the engine may include the following:

  • fuel pump replacement;
  • disassembling and flushing the strainer;
  • replacing the adjusting lever;
  • it is also necessary to clean the adjustment space;
  • replace the diaphragm (or the entire unit where the diaphragm is located);
  • Adjusting the intake, exhaust and needle valves;
  • Damper replacement;
  • cleaning the fuel ducts and diffuser;
  • replacing the screw springs;
  • primer change.

Not all of these jobs can be done. Many of these are often unnecessary if a particular fault is detected immediately.

Adjustment lever fails

Wear of the lever contact faces. the consequence of not perfectly clean fuel in which grains of sand or particles of clay, metal or other inclusions not soluble in liquid hydrocarbons got. Injection problems appear, and the engine does not run smoothly under no load.

Damper is worn out

Throttle and air damper deteriorate due to dust, metal particles, etc. entering with the air stream. д. Damaged flaps look like parts that have been blasted with sand. Flap wear reduces the efficiency of the motor and causes breakdowns. Piston and cylinder wear out.

Flaps fail due to improper maintenance of the air filter or its breakage.

In some cases the filter may not fit your brushcutter or grass trimmer. The motor shaft will eventually be damaged, pieces of it will get into the channels of the motor and the piston will be broken.

The carburetor cannot be adjusted

That the adjustment is too rough (can not be accurately set the parameters) are to blame for the springs on the adjusting screws. The manufacturer of a brushcutter or grass trimmer may have put excessively thick and stiff springs. Find others can either be found in shops where similar equipment is repaired, or purchased from any dealer or an official representative of the company that produced the motor for your grass trimmer or mechanical grass mower.

How to adjust a lawn mower carburetor?

Lawn mower or grass trimmer, despite its relative simplicity (compared to the car engine), sooner or later fails. There comes a time when long downtime and restarts are not enough for a gasoline-powered machine. maintenance is needed. In neglected cases, repairs are required, or rather, replacement of worn parts with the same new ones. Until you are faced with the need to replace worn parts, you need to service the carburetor. cleaning, flushing, readjusting mechanisms.

The structure of a carburetor

The lawnmower (lawnmower) has a base. a housing made of aluminum in which the other parts are assembled and function as one unit. In the body of the carburetor there is a diffuser. a passage with internal channels, through which air is pumped.

The larger the cross-section of the diffuser, the more actively oxygen is supplied together with the air. an oxidizer in which the fuel (petrol-oil mixture) is combusted.

Channels branching from the diffuser stroke deliver fuel, with which the discharged air mixes with and entrains petrol vapours. Outside the main section of the carburetor are located:

The latter forms the very rattle mixture that ignites in the carburetor combustion chamber.

Working principle

The order in which the fuel is pressurized and filtered in the lawnmower engine is as follows.

  • The throttle valve is used to set the amount of air supplied to the diffuser. The more air is supplied, the more oxygen the gasoline needs for combustion and the more power it produces in the form of heat. The heat energy is further converted into mechanical energy.
  • The diaphragm pump squeezes the necessary quantity of petrol.
  • Then the petrol flows through the engine nozzle.
  • Fuel flows through the inlet and outlet valves.
  • The fuel is filtered with the help of the mesh filter.
  • It flows through the needle valve into the diaphragm chamber.

The steps of the carburetor are as follows.

remove, carburetor, lawn, mower
  • The air flows into the air duct with an air damper. The choke sets the correct intensity of air flow.
  • The diffuser in the gasoline injection unit is narrowed to give more speed to the airflow.
  • Fuel passes through the float chamber and bypasses the nozzle and gets into this narrow tube. The float catcher regulates the gasoline flow. In this compartment the pressure is in a state of equilibrium. In the narrowed tube, it goes down. Because of the difference of both pressures gasoline passes through the nozzle.
  • Accelerated flow atomizes gasoline, converting it into aerosol vapor. The resulting gasoline-air mixture is ready to be ignited in the combustion chamber.
  • Passing through the fuel line, this mixture ends up in the carburetor cylinder.

Conclusion: in order to set the desired power, you first adjust the combustion rate with the air damper. If the gap is too small and the oxygen in this mixture is less than 10%. fuel does not burn, therefore, the engine will not start or immediately stop.

In the case of buying a Chinese grass trimmer is worth considering that it is little different from the European. the same 2 or 4-stroke engine and drive.

However, they save on the quality of parts, forcing the consumer to change them more often. Check what compatible parts are offered by non-Chinese companies for your device.

Step 7

Lubricate the mechanical connection that is attached to the top of the metering rod. Check that the mechanical clutch moves freely by tapping it several times.

How to Make a Correct Adjustment

Before you start adjusting the grass trimmer carburetor, do the following:

  • Flush the motor;
  • Replace or clean the spark plug;
  • Replace with a new one or clean the air filter (it is recommended to wash it in warm, soapy water, squeeze it and let it dry well).

You also need to put a cord with a proper diameter in the trimmer spool or install the blades, this is done so that the motor has some load during adjustment. After installing the cutting attachment and starting the gasoline engine, let it warm up for 10 minutes.

If you notice that the cutting attachment is rotating while the engine is idling, you need to decrease the engine speed. This is done with the lower idle speed control, often marked with a “T”. The illustration below shows the location of the regulators on the Husqvarna trimmer.

But on a STIHL trimmer, for example, this screw may be marked “LA”.

So, turn the idle speed regulator to the left until the trimmer head comes to a complete stop.

There are three regulators (screws) for adjusting the carburettor.

  • The L knob on the right adjusts the fuel-enrichment level at low rpm. It needs to be adjusted first. Reach maximum idle speed. This is done with the L control by turning it to the left and right. Once you have found the maximum RPM point, turn the regulator half a turn to the left (vs. arrows).
  • The lower regulator T (LA) is used for adjusting the idle speed. Turning it to the left will begin to decrease the engine RPM, and turning the knob to the right will increase the RPM.
  • The left-hand H regulator is responsible for enriching the fuel mixture at high rpm. Setting the choke up completes the carburetor adjustment. The maximum rpm, fuel consumption, and engine output can also be adjusted with this knob.

Important! If you let the engine run at full rpm for more than 10 seconds, it may be damaged.

In order to avoid this unpleasantness an adjustment is necessary. With the engine running give full throttle and then turn the regulator “H” to the right until the revs begin to decrease. Then slowly turn the knob to the left until you hear a jerky sound from the engine. Then turn knob “H” to the right until a smooth engine rumble is heard.

remove, carburetor, lawn, mower

After the above actions, adjustment of the carburetor can be considered accomplished. After proper adjustment, the engine should confidently gain revolutions, slightly even at maximum rpm, and when idling, the cutting tool should not rotate. This manual is suitable for adjusting the carburetors on Huter, Patriot, and other chain saws.

There are also carburetors without a screw, which is responsible for enriching the fuel mixture at low rpm. That is, they have only 2 adjusting screws: the idle speed regulator and the fuel mixture quality regulator at high RPM. How to adjust this type of carburetor, you can learn from this video.

The Makita ELM 3700 lawnmower is broken

Actually I bought my lawn mower Makita ELM3700 last year. Old fool, I did not look how the blade is fixed on plastic thing, which is both a fan that drives grass and cools the engine. Only Chinese people drunk on sake could come up with that. Well, of course, with a good blow, on this very fan srubilo chip, the centering knife. The lawnmower is vibrating now, the blade can’t be centered. I tried to take it off, hoping to buy it separately, but it’s not working. It is pressed hard on the engine shaft. I tried to heat it up, it won’t work. It turns out that it is a one-time use, and in case of an accident, it can only be replaced with the motor? Any idea how to center the blade? I assume in place of the chips to drill holes and put screws.

We will try to answer the question: repair gasoline lawnmower Makita with their own hands on the recommendations of the true master with the most detailed description.

Active use of garden equipment leads to the rapid failure of individual components or parts. There is no need to dispose of the equipment, because it can still be useful in the future. Sometimes with a little help from your own hands, you can bring your lawn mower back to the way it was before it was supposed to be.

Depending on the area of the lawn and the growth of grass on it, the owners choose the optimal technique in terms of characteristics. It comes in several types:

Lawn mower fuel pump check

An average-priced mower can withstand in the climatic conditions of St. Petersburg, Moscow or similar regions for about four seasons. expensive or less exploited garden helpers are able to endure in the field for 5-6 seasons.

Also, the restoration of lawn mowers with their own hands will be needed in the event that the conditions of winter storage were improper. For example, after use there was no cleaning of working surfaces or absence of interseasonal preventive maintenance. As a result, a variety of problems appear:

  • Frequent sharpening of mower blades is required;
  • the lawnmower just won’t start;
  • motor starts, but after a short period of time the lawnmower cuts out;
  • there are malfunctions in the carburetor, which requires not only disassembly, but also cleaning with repair;
  • Repair of the lawnmower with their own hands is required in case of a significant decrease in power during operation.

It is not necessary to go to an expensive service center. Many problems can be solved inexpensively and repaired on your own.

The cutting parts need to be cleaned after each use. Change oil and service regularly to minimize the risk of breakdowns.

Mowers with electric motors inside are prone to getting cranky because of oxidized contacts. Clamps become encrusted with scale from excessive moisture in the room or in another storage area. It is also worth checking for broken wires in problematic areas. Use a multimeter or other type of tester for this operation.

remove, carburetor, lawn, mower

When a set of gardening equipment contains a brush motor, then reveal the operability of the moving unit. Brushes can wear out quickly, causing a loss of contact. Repair kit with them costs relatively little, and it is easy to find in specialized stores, where they sell spare parts for such equipment.

Faults also occur in asynchronous motors. There is a failure of the phase shifting capacitors. This situation is difficult to diagnose at home. It can be detected by indirect symptoms:

  • a humming sound is heard;
  • The housing jerks slightly when starting;
  • Significant heating of motor even under light load
  • RPMs decrease.

How to Fix a Lawn Mower by Cleaning the Carburetor [Briggs & Stratton and Tecumseh]

It is worth carrying out diagnostics of the state of the toggle switch/button and supplying voltage to the electric motor. When the test described nodes, and no malfunctions are found, it is unlikely to fix the breakdown of the lawnmower with their own hands. Then you have to use the service of company.

Initial diagnosis is carried out from the stage of elimination of the most obvious breakdowns. When the engine does not start, then it is worth checking the presence of fuel in the tank. If there are remnants from last season, it is worth replacing it. Low-quality gasoline after wintering can lose its characteristics, give unwanted sediment or even split into fractions in density. In this form it is not able to start the engine, but only clogs the system.

No thematic video for this article.

In the second step, find out why the spark does not appear. Its loss will not allow the fuel to ignite. Remove the cap from the spark plug and unscrew it from its seat with the special key that came with the mower. Next, put the cap on the spark plug, bring it close to the threaded part or metal part of the motor, while your partner pulls the starter.

With such manipulation, a blue powerful spark must appear in the working node. It can be seen even in daylight. It is important to test this next to an unpainted metal part of the motor that can conduct current.

When there is no spark, you must go to the store to buy a new spark plug. Do not return to the motor even if the spark is weak or unstable. It is better to clean working pins of carbon on the head beforehand.

Rattling in the structure may occur during operation. It at first does not affect the performance of the mechanism as a whole. However, can lead to imbalance and increased noise during operation. It is worth retightening the fastening screws on the frame in a timely manner.

Tightening the mounting bolts on the frame

remove, carburetor, lawn, mower

Uneven cutting of the grass is a sign that the mower blade needs sharpening. It is not difficult to get to them, but it is important to completely disconnect the equipment from the power supply. The work can be carried out independently by means of a vice and file or on a sharpening machine. It is important to ensure that the angle of cut is uniform throughout the line of 30 degrees. If there are chipped areas in the surface, it is an indication of hitting a hard surface. Replacing them is quite expensive.

How to make repairs to the lawnmower with their own hands?

Those who have land plots are very familiar with what is the fight against weeds.

Especially when it rains a lot and the grass grows by the hour. Previously, and sometimes even now, this issue was solved with the help of a good old-fashioned grass mower.

But technology is not standing still, and now in this business to help such assistants, such as electric and gasoline lawn mowers.

The gasoline mower has some great advantages over electric mowers, such as mobility and no danger of electrocution. But there are also many disadvantages, such as: high price, a lot of noise, expensive fuel and great weight.

Electric mowers are cheaper, lighter, operate on inexpensive energy, and are not difficult to maintain and repair. These advantages are the main reason of their great popularity among the buyers of this kind of equipment.

But despite the rather good quality, improper use and a heavy load, can break the machine. In such cases, do not immediately carry the device to a repair shop, but try to find and eliminate the cause of the breakage yourself. over, as mentioned above, electric lawnmowers do not have as many nodes and parts as gasoline mowers.

The main thing is to have some tools and faith in yourself. In this article, I will just show you how to do the repair of lawn mower with their own hands.

We’ve taken an AL-KO lawnmower as an example and it has some serious operational problems, namely, the engine stops with no load and overheats heavily. The motor stops, it hums and start it again, it helps only to press the “START” button again. You have to restart the button almost every 30 seconds, or more often if you continue mowing.

Of course, you can work this way too, but it’s very annoying and gives the feeling that there is a problem somewhere. So I wanted to find out where?

After running the mower for an hour the temperature of the engine was measured. You can’t put your finger on it. It was just radiating heat. If you keep ignoring it and keep working with such a mower, the motor will break down inevitably.

The cause of the overheating of the motor needs to be determined. To do this, you have to remove the top cover of the housing, under which the motor and its power circuits are located.

The cover is fastened with six screws with a Phillips head screwdriver.

We unscrew these screws and remove the cover upwards.

After taking it off you can see the impeller, the capacitor, the two connectors and the motor itself.

At a glance there is no particular problem. The motor winding is a bit dark from the temperature, but for the moment it is not critical.

To inspect the condenser more closely, you need to unscrew the mount and pull it out.

The condenser did not show any external damage.

To check it, you need to disconnect the capacitor and power the motor for a short time. If it doesn’t start and starts humming then the capacitor is intact because the motor started with it. Disconnect the power supply and connect the receptacle connector back to the motor circuit.

Next, try to spin the impeller. It’s mounted on the axle of the rotor and it turns quite tight.

And the reason of such heavy rotation, is a mechanical brake, which for safety, stops the rotation of the motor when you turn off the power.

It looks like a sleeve that slides freely from top to bottom in the axis of the rotor.

When the motor is not energized, this sleeve is pressed by the upper part against the cover, on which two rubber strips are glued. This brakes the blade attached to the rotor shaft.

When power is applied, the brake sleeve, under the influence of a magnetic field, retracts to the center of the rotor and allows free movement.

On close inspection of this sleeve with brake it was noticed that the moment the motor is turned on, the brake retracts and gives the shaft a free rotation, but after 2-3 seconds it is released again and starts to brake the motor. That shouldn’t happen. Hence the stopping of the blade during operation and overheating of the motor.

To find out what is the cause of this work, you need to remove and disassemble the motor.

To do this, disconnect the connectors and put the machine on its side to get to the clamping screws. Access to them closes the knife with the elements of fastening.

To remove it, first you need to unscrew the bolt securing the knife (see the picture below). figure below).

Direction of rotation, like a normal bolt, not with left-hand thread. That is, it should be unscrewed counterclockwise and screwed in clockwise.

The head of the bolt is plastic, so using a wrench, you must put it on well so as not to “lick off” the facets.

Instrument adjustment

After all the premature work has been done, you should already resort to adjusting the engine carburetor.

First of all it is necessary to do what the good work of the machine depends on. idling speed. Here it is necessary to consider uninterrupted operation at a speed of 50 km/h. It is necessary to make the car move quickly and leisurely.

Using the screws to adjust the idle speed of the vehicle. After that, you should turn on the motor. It is necessary to understand that if after these manipulations the car’s revolutions become significantly lower, it is necessary to return them to their normal state.

The next step is to put the propeller in such position in which the car would move at the same pace and without stopping.

Then it is necessary to find the point of the propeller at which the engine stops working in such conditions. This operation is necessary to find the correct screw position, in which the amount of CO is the smallest.

To check if the adjustment is correct, turn the screw responsible for the engine rpm during operation.

If after these manipulations your car has stalled, then we can congratulate you! it means that the tuning of the car is correct.

Setting the grass trimmer carburetor

The initial step in restoring the correct operation of the fuel system is to clean the air filter.

Experts recommend after every 10-15 hours to wash it in a solution of water and detergents. The direct adjustment of the grass trimmer carburetor is made with three adjusting screws:

  • Fuel adjustment screw (“L”);
  • Adjustment screw at high revs (“H”);
  • The screw responsible for engine operation at idle (“T” or “AT”).

Adjusting the fuel supply at minimum rpm

Before you start adjusting the carburetor of the gasoline triimeter you need to warm up the engine to working temperature.

For this start the engine and idle give it to work 10-15 minutes. On the first step, with the trimmer in operation, slowly turn the L screw until intermittent operation is felt or until the trimmer stops. Next, unscrew the screw by ¼ of a turn and check the speed of maximum rpm. If the lawnmower quickly and easily reaches high revolutions, this is the most economical mode. In most models available on the market the fuel screw “L” is tightened clockwise, but there are trimmers for grass, where the reduction and increase the mixture occurs in reverse order.

Grass trimmer idle speed adjustment

Location of carburetor adjustment screws

Screw “T” (“AT”) serves as a limiter of reciprocating motion of the fuel flap and screwing it increases the engine speed, and unscrewing it leads to a decrease in speed of the crankshaft. Professionals recommend setting the mower idle speed screw so that the engine is running slightly faster at minimum rpm but the cutting head with the line or blade stays still. If it is difficult to start the brushcutter when it is cold after carrying out a few manipulations, turn the “T” screw a quarter turn and then restart the engine.

Maximum engine speed screw adjustment

After restoring the fuel supply at minimum rpm and adjusting the idle speed, check the stability of the machine at higher rpm.

Use the high RPM setting to protect the engine from overheating and to reduce hand fatigue when pressing the gas pedal button. If the engine does not reach a constant maximum rpm, turn the maximum rpm setting screw “H” slowly until you get a smooth and clear cut.

If the trimmer is difficult to start after operating the machine, you may need to adjust the fuel selector switch (“L”) for optimum RPM.

Recommended corrective measures

The list of upcoming works with the engine can be as follows:

  • replacing the fuel pump;
  • disassembly and flushing of the strainer;
  • replacing the adjusting lever;
  • it is also necessary to clean the adjustment space;
  • replacing the diaphragm (or the entire unit where the diaphragm is located);
  • adjusting the intake, exhaust, and needle valves;
  • replacement of the flaps;
  • Cleaning the fuel ducts and diffuser;
  • replacing the screw springs;
  • primer change.

Not all of these jobs can be done. Often it turns out that many of these are unnecessary if a specific fault is immediately detected.

| Denial of responsibility | Contacts |RSS