How to Adjust a Stihl 250 Chainsaw
Chainsaw carburetor. This is one of the main components of this tool. He is responsible for the fuel supply. The effectiveness and power of the equipment depends on how well this unit functions. Timely adjustment also provides cost-effectiveness.
Before setting up a carburetor on a chainsaw, you should find out that adjusting this part of the device is quite rare. As a rule, the factory setting is enough for normal operation. However, if more precise adjustment is required, then special screws can be used. Before starting such work, you need to understand the intricacies and nuances of the process.
When carb adjustment is required
If the adjusting screws happen to be loosened, the carburetor should be adjusted. Other signs may also indicate the need for these manipulations, among them:
- breakage of the protective cap;
- significant piston wear;
- outages in the motor;
- strong vibration;
- lack of response from the engine when trying to start the tool;
- increase fuel consumption;
- strong exhaust.
If piston wear has occurred, it will also be necessary to repair the motor, but adjusting the carburetor will be a temporary measure, and the unit will become more stable. If the described unit turned out to be clogged, which led to interruptions in the operation of the motor, then it will also be necessary to flush it.
Whereas when a situation arises when the engine stalls or does not start, we can conclude that the working mixture was depleted. Abundant exhaust also indicates incomplete combustion of the fuel mixture. This conclusion can be reached if the tool began to consume fuel in an excessively large amount.
In order to get to the carburetor, bolts are unscrewed on the tool cover. The housing must be opened and the foam, as well as parts of the air filter, must be removed. Only now you can begin to adjust. Before setting up a carburetor on a chainsaw, you should find out that the main task of these works is to change the quantity and quality of the air-fuel mixture, which is pumped into the combustion chamber of the engine.
During work, you should be guided by certain rules, among them:
- the chain must be directed to the side;
- the equipment should be laid on a flat surface;
- Cutting parts must be removed to a safe distance.
The first requirement is due to the need to exclude injury. If you were wondering how to set up a carburetor on a chainsaw, you should know that it is necessary to carry out these works using three screws. The first of them controls the jet and is indicated by the letter "H". It is necessary to adjust the maximum speed.
The second screw can be found by the letter “L”. This unit is necessary to control the idle jet at low shaft speeds. Quite often, novice masters ask how to set up a carburetor on a Partner chainsaw. In it, the third screw is indicated by the letter "T". It is needed to adjust the idle speed. The adjustment process is divided into stages:
The first is when the engine is off, while the second is on a warm engine.
Basic adjustment step
First you need to use the speed screws. They are wrapped all the way clockwise. Then turn back one and a half turns.
Before setting up the carburetor on the Husqvarna chainsaw, you need to find the third screw, which is indicated by the letter “T”. Then the engine warms up for 10 minutes at medium speed. The third screw must be turned counterclockwise until the motor starts to run stably. The chain must be stationary.
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If the motor stalls idling, the screw should be turned clockwise. When the target moves, the screw is twisted back. If you are faced with the question of how to set up a carburetor on a chainsaw, in the next step you should check how correctly the engine operates at maximum speed during acceleration. It should be assumed that the engine functions correctly during acceleration if, when the accelerator is pressed, rpm increases to a maximum value between 2800 and 15000. The screw marked “L” must be unscrewed to the left by an eighth of a revolution.
Maximum RPM Adjustment
Before setting up the carburetor on the Partner 350 chainsaw, you must find the “H” screw. It is necessary to adjust the maximum speed. It should be rotated clockwise, while if it is necessary to reduce the number, then the movement of the screw should be directed in the opposite direction.
The maximum frequency should be set between 11500 and 15000 rpm. If this value is exceeded, the engine will run to wear, which will certainly lead to a violation during ignition. When rotating the screw under the letter "H", you must take into account how the ignition occurs. If a malfunction occurs, the rotation should be stopped by turning the screw counterclockwise.
You should know how to set up a carburetor on a Chinese chainsaw. In this case, a further check is carried out at idle. As soon as the adjustment in acceleration mode has been completed, it is necessary to bring the tool to idle. If you did everything correctly, the chain will remain stationary, and the motor will gain momentum in a short time when you press the accelerator.
You should also listen to the engine. The sound should look like a four-stroke unit. If you are thinking about how to properly set up a carburetor on a chainsaw, you should make sure that the above conditions are met. If this is not so, then the adjustment must be repeated, while the basic stage is omitted. You should not take up the job if you do not have enough experience, because in this case the knot deregulation may occur. When self-tuning is not possible, stable work can be achieved by contacting professionals.
The nuances of adjusting the carburetor chainsaw brand "Stihl MS 250"
You may have a question about how to set up a carburetor on a Stihl chainsaw. First you need to decide when such a need arises. The described work may be required if the spark plug electrodes have changed color. When it turned out to be black, this indicates re-enrichment, while with a brick-gray color you can be calm, as this is the norm. When the master notices a white coating, he can be sure that the mixture is depleted.
The main role in the adjustment is played by the upper screw; it is located closer to the muffler in the described model. If you follow the factory parameters that you can find on the tool cover, then this screw must be unscrewed one turn, and then carry out the adjustment. When unscrewing, the mixture will be enriched, whereas if the screw is screwed in, the mixture will be depleted, while less gasoline will get into the air-fuel mixture.
Recommendations of the specialist for working with the carburetor of the Druzhba chainsaw
Before setting up the Druzhba chainsaw carburetor, you must perform tool maintenance. It involves flushing the engine, cleaning the carburetor, replacing the spark plug, checking the chain tension, cleaning the air filter, warming up the engine and adjusting the idle speed. As soon as the screws “H” and “L” are fully tightened, they must be unscrewed one turn. Do this with a muffled chainsaw.
Then the tool warms up, full throttle is given, and the first of the mentioned screws rotates in such a way as to reach 14,000 revolutions per minute. The maximum speed should be held for 10 seconds or less.
By turning the last screw, make sure that the chain begins to move. Then the bolt is turned a quarter of a turn counterclockwise. If after this the idle speed is not so stable, and the tool accelerates slowly, the screw marked “L” must be turned counterclockwise, only then the chainsaw will gain speed.
It is important to remember that adjustment will not work if air is drawn into the engine from the side. This can happen through:
- accelerator pump;
- gasket under the carburetor;
- crankshaft oil seals.
After completing the procedure, the engine of the tool can be started by warming it for 10 minutes. In this case, you can set the average speed. Then you can do the idle screw.
For work, you will need not only a flat surface, but also a tachometer, by which you can identify violations in the operation of the adjustable unit. When the revolutions of the screws, the sound should be even, if you notice a squealing note, then this indicates that the mixture is oversaturated.
If you do not have enough experience, then before starting work, you need to familiarize yourself with the principle of the carburetor, which functions in the same way as an internal combustion engine. This provokes a small explosion that occurs in the ignition cylinder of the mixture. Pressure from this process pushes the piston, which rotates the crankshaft. The movement develops into a rotation that moves the chain through the sprocket. With optimal operation, the engine consumes up to 10 mg of fuel in each cycle. Whereas the mixture for the motor is prepared in the carburetor.