Carburetor Adjustment Of Chinese Lawn Mowers

Build your Home! This article is about DIY lawn mowers carburetor repair, we will show you how easy it is!

How to purge. The most effective way is to use an ultrasonic bath.

carburetor adjustment of chinese lawn mowers

It is filled with either a special liquid or gasoline, a carburetor is placed there and under the action of ultrasound, the so-called cavitation effect, the channels are cleaned of contamination.

The second option for cleaning is compressed air.

You can use the compressor available on the farm and clean the carburetor channels. However, this method is effective if the pollution is not very large.

Dismantling the carburetor

A visual inspection of the carburetor will help detect fuel leakage and air leaks, but the main reasons for the failure of the device lie inside. Therefore, in order to determine and most importantly fix a breakdown, the carburetor must be disassembled.

It doesn’t take much effort to disassemble the carburetor for lawn mowers.

It is enough to unscrew four screws on one side

And two on the other. This can be done using a regular Phillips screwdriver. Carefully unscrew the screws and fold them to the side. They may be needed during assembly. It is advisable to cover the table with a white cloth before disassembling so that you can see everything, even the smallest details that may fall out during disassembly.

Step 17

Turn the carburetor over and go to the fuel system assembly. First you need to put the gasket.

Adjusting and repairing the carburetor lawn mowers

The trimmer does not belong to complex household appliances, therefore most of its breakdowns are mechanical in nature and are quite successfully eliminated with their own hands. Even if the engine fails for serious reasons, damage to the piston ring, for example, repairs are reduced to replacing a part.

But even with a relatively simple design, such a part of the device as the carburetor needs to be adjusted.

Principle of operation

The carburetor is a power system module in which liquid fuel and air are mixed before being fed into the engine cylinders. Mixing and feeding are adjusted accordingly depending on the tool and its mode of operation.

The carburetor device for lawn mowers is the same for almost all cases. It belongs to the category of float devices. The latter provide stable parameters of ready-made mixtures.

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The principle of the module is as follows.

  • Air enters the body of the air damper tube. The latter increases or decreases the air flow depending on its position.
  • In the area where the gasoline feed hole is formed, the tube has a narrowing diffuser. Here the flow rate increases.
  • Fuel from the float chamber is fed through the nozzle into the tube. The float level determines the amount of fuel supplied. Since the pressure in the chamber is normal, and in the tube it is low due to the greater rarefaction of the air, gasoline is sucked in through the nozzle.
  • The accelerated air flow picks up the fuel and sprays it, forming an air-fuel mixture of the desired density.
  • The mixture is sucked into the cylinder through the pipeline.

The more open the air damper in the tube, the higher the density of the air flow, which means more fuel enters the cylinder. Adjusting the carburetor of lawn mowers is reduced to setting such a ratio of flaps, at which the density of the fuel mixture becomes optimal.

Signs of imbalance

Debugging the carburetor must be done during the manufacture of the device. As a rule, the owners will learn about the need to adjust the fuel supply with their own hands only after serious enough breakdowns, in the process of correcting which, the module was removed and, for example, cleaned.

Signs of a configuration failure are the following:

  • Starts, but the engine immediately stalls because the engine can only work when a certain amount of gasoline is supplied, with too lean fuel, that is, blocking the supply channel, the engine will stop;
  • Too high fuel consumption, a lot of exhaust gases are the result of incomplete combustion of the mixture. In this case, on the contrary, there is too much fuel and the mixture is too dense.

Fuel supply adjustment

Begin to slowly tighten the fuel mixture adjustment screw until the engine starts to stall or stalls if you do not have time to catch the moment. After that, unscrew the screw a quarter of a turn if the engine has not stalled, or half a turn if it stalled. Start the stalled engine. Check by opening the throttle as the engine picks up speed. Continue to unscrew screw # 1 by a quarter of a turn until the engine starts to accelerate steadily during gas blowing. This will be the moment of the most economical stable engine operation. For the PRORAB-8406 petrol trimmer, the adjusting screws are turned clockwise, unscrewed counterclockwise, for some other brands of lawn mowers it may be the other way around.

Spring may interfere

My first attempt to adjust the carburetor of the lawn mowers did not work, as the spring of the screw for adjusting the fuel mixture interfered with. The factory spring turned out to be too thick when compressed and did not make it possible to reduce the fuel supply to the required level. I had to pick up another spring and continue adjusting after replacing it.

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Fuel mixture adjusting screw with spring

In the photo above the factory spring, below the adjusting screw with the matched spring. I am writing about this because I’m not sure if this is an isolated case, and someone else may face the same situation.

Adjusting the carburetor lawn mowers, trimmer

Increased fuel consumption and the rapid formation of carbon deposits on the spark plug when using a properly prepared fuel mixture indicate the need to adjust the carburetor. Here’s how to tune trims with carburetors that have one fuel trim screw.

Find the highest idle speed by slowly turning the screw to the left or to the right. After finding the maximum rpm position, turn the screw counterclockwise на turn.

Note: FORTE lawn mowers are shipped from the factory with the right screw completely unscrewed (0.5 turn). At this stage, he should be looking at 11 o’clock.

Bottom screw T. Responsible for adjusting the engine idle speed. Turning the screw counterclockwise decreases the number of revolutions. Counterclockwise increases.

Carburetor adjustment FORTE lawn mowers

The gasoline lawn mower has been successfully used for a long time in a variety of industries: for lawn maintenance in private plots, in housing and communal institutions, landscaping organizations, agriculture and forestry. The main competitive advantages of the products. Low maintenance costs, increased reliability and ease of use.

Engine. The most important component of any technique. And so that it always works in the optimal mode for itself, it is recommended to fine-tune the carburetor.

How to repair the carburetor of lawn mowers with your own hands and why do they recommend doing this? First of all, to make sure that the engine is working properly and that the maximum productivity of the tool is ensured 100%.

FORTE Lawn Mowers Carburetor Setting:

1. Start the engine of the device and let it warm up for 10 minutes (if you observe the rotation of the cutting element at idle speed, turn the idle screw in the opposite direction, turn until the spool stops turning).

2. Gently rotate the right and left needles to the middle position. Important! Never twist the stopper; this may damage the engine).

3. There are 3 adjusting screws to adjust the carburetor:

  • Right H low speed screw
  • Bottom T screw idle
  • Left L high speed screw
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Right screw H. First of all, the low speed screw is adjusted.

Correct adjustment is considered only if:

  • Cold engine at idle running stably without jerking
  • A hot engine gives out understated revolutions in idle mode
  • Sufficient headroom remains before the cutting system starts to work
  • Stable engine operation in any position

Note: From the FORTE factory, the lower screw H (idle), from a fully tightened state, was unscrewed by 8 revolutions and 2 hours (at this stage it should be). Recommended idle speed for FORTE engines is 2900 rpm.

Left screw L. Fine adjustment of the highest idle speed.

Important! The engine of FORTE petrol lawn mowers should not run at maximum speed for more than 10 seconds.

Open the throttle, start the engine and lightly turn the screw clockwise until the engine speed decreases.

Then slowly turn the screw L in the opposite direction until the engine starts to shake.

Finally, turn the screw clockwise a short distance again until the mower engine starts to operate in the appropriate mode for itself.

Do-it-yourself lawn mowers carburetor adjustment

Lawn mowers, like all gas powered garden tools, are not difficult to maintain. It is possible and necessary to repair, configure yourself. For example, adjusting the carburetor of a lawn mower with your own hands is a matter of five minutes.

A lawn mower carburetor is a unit in the power system. In it, like any carburetor, there is a process of mixing air and fuel (gasoline) for further supply to the engine cylinders.

The main problems and malfunctions of the carburetor.

Mesh filter. There are often only two problems with this element:

  1. Blockage.
  2. Breaking.

In order to find out the cause of the breakdown, the fuel filter cap is unscrewed to remove the strainer. If dirt just accumulates on it, then flushing in gasoline or blowing will help.

If there is visible damage to the mesh filter, it is imperative to install a new one. There may also be damage to the fuel supply pipe (during repair, they practice checking this element).

The carburetor starter in most cases does not function due to blockages. Use acetone or the same gasoline for flushing.

Blowing compressed air into carburetor parts is an acceptable and convenient repair practice.

Lawn mowers carburetor device

The base of the carburetor is an aluminum body. It contains a diffuser (hole with internal contours). Air is blown through this hole. The flow rate of oxygen (air) depends on the cross-section (orifice) of the diffuser.

The diffuser is equipped with fuel channels. Fuel is drawn in from them using an air stream.

Outside the carburetor is installed:

  • Fuel pump;
  • Jet system;
  • Fuel-air mixture control system;