Carburetor Adjustment Lawn Mowers

Chainsaw carburetor adjustment

Carburetor Adjustment Lawn Mowers

Gasoline saw. The most popular gardening equipment, which has long been very popular among gardeners and owners of private houses. Not a single event in the field of construction and repair work can do without it. Well, if we talk about the profession of a lumberjack, then we can say with confidence that such a tool is an essential element, without which there is nothing to do in the forest.

However, like any complex equipment, a chainsaw requires periodic maintenance. For example, in the case of excessive loads, malfunctions may occur with its operation, which often entail unexpected and very unpleasant consequences.

In our case, we will talk about the device responsible for supplying the fuel mixture to the combustion chamber, namely, the chainsaw carburetor, on the correct operation of which it depends on how powerful and at the same time economical the equipment will be. Therefore, if you notice a clear error in the operation of your saw tool, the first thing is recommended. Adjust the carburetor.

When is adjustment necessary ?

Inaccurate operation of the carburetor, which can be lost due to the shift of the adjusting screws.
Piston group wear
Blockage of the carburetor (in this case, it is necessary not only to adjust it, but also to disassemble it with subsequent cleaning).
Frequent temperature changes combined with high humidity in the room where the instrument is stored.
Incorrectly selected fuel mixture (try replacing the fuel, if the result does not follow, adjust the carburetor).
Increased vibration.
The engine does not start or stalls after starting.
Fast fuel consumption and abundant exhaust.

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Carburetor device

The structure of the carburetor may differ in different chainsaws, but the principle of its operation remains the same. A fast air flow moves in the direction of the air channel, the speed of which is regulated by a special valve that closes the outlet. Fuel is sprayed into the duct and mixed with the incoming air stream to create an air / fuel mixture. After which the resulting composition is fed into the engine.

Purpose of carburetor tuning. Ensure the correct quality and quantity of combustible material entering the combustion chamber. If the ratio is incorrect, the correct operation of the engine is compromised.

Dismantling the carburetor

Since the carburetor design appears to be the same for all models, the new professional model will be used as an illustrative example. Gasoline saw Grunhelm. However, it should be noted that the problem on which the tool ceased to function must be sought gradually, from simple to more complex. Disassembling the mechanism, without identifying the reason, can turn against you. But if such a need nevertheless arose, for example, it was required to clean it from dust and dirt, then this must be done very carefully.

Step-by-step instruction :

Carefully remove the top cover by turning the special plastic screw.
Inside we will see a component of the air filter, which also needs to be removed.
To get full access to the carburetor, take a screwdriver in our hands and unscrew the three screws located on the sides of the case.
Then we remove the fuel pipe and drive rod.
Carefully remove the cable end and disconnect the gasoline hose.
Having done all these manipulations. Finally, we release the carburetor.

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Do not forget that its design is quite complex, so it is worth removing all the elements with increased accuracy. The contents of the carburetor consist of a large number of small parts that can easily get lost.

After disassembly, it is necessary to troubleshoot the mechanism, replace deformed or worn parts, and clean and dry the entire set. Make sure the air filter is not clogged with dirt and dust. Then reassemble in reverse order.

Precision work must be carried out exclusively on a hot engine. Therefore, start the engine and warm it up for 10 minutes. Then turn the adjusting screw counterclockwise to stop the chain.

Place the tool on a firm, level surface before starting carburetor adjustment. Point the saw head in a direction safe from injury. Remove objects that are near the cutting edges of the tool.

To adjust the operation of the carburetor, three screws are used, each of which has its own designation:

H. Controls the main jet, designed to adjust the high speed.

L. Controls the idle jet, is used to adjust low rpm.

T. Idle setting.

Adjustment is carried out with screws “H” and “L”. To lower the octane number of the chainsaw, the knobs are scrolled from left to right (clockwise). This procedure increases the engine speed. To increase the octane number, the screws are turned in the other direction, from right to left. Thus, low revs are set.

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The adjustment sequence looks like this: L → H → T.

Turning the screw “L” to the maximum, from left to right or in the opposite direction, we find the limiting number of rotation. Then we return to ¼ turnover.

On a warmed-up engine, using the same principle, we perform actions with the screw “H”. Let the saw run for a few seconds. Armed with a tachometer or good hearing, we determine the maximum speed by sound. It must correspond to the value specified in the instrument passport.

If the chain is in motion at idle speed, turn the regulator “T” in the same direction until it stops completely.

Draw your attention to, that in the case of inaccurate determination of the RPM point by the regulator “H”, the engine will fail and it will require expensive repairs that take a long time.

The idle speed is adjusted with the “T” screw. The regulator rotates counterclockwise (from right to left) until the chain stops completely.

When adjusting the carburetor correctly, you should observe:

Fast engine acceleration.
Distinct engine sound like a four-stroke mechanism.
No chain movement when idling.

We hope that our article helped you solve such a problem as adjusting the carburetor of a chainsaw, and you will be able to carry out this maintenance yourself. If you have doubts during the adjustment process, then it is better to entrust this process to the employees of a specialized service center, where there are all the necessary components for the repair of equipment.

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