A chainsaw is a popular tool both on a village farmstead and in housing and communal services. It has a large motor resource and can work for many years, with timely maintenance. However, it happens that the chainsaw stalls in the middle of work. What to do in this case: carry it in for repair or try to fix it on your own?
At the heart of any gasoline tool is the operation of the internal combustion engine. Having understood the causes of chainsaw malfunctions and learning how to fix them, you can fix the breakdown of any device.
Types of chainsaw malfunctions
Practically on any hand-held petrol tool, a two-stroke engine is installed as a power unit. These motors have advantages over four-stroke ones. They have a lower mass at the same power. But along with this, they got flaws in the form of adding oil to gasoline and lower profitability. There are several basic malfunctions in the work of the saw:
- The engine will not start. Starting a cold engine and a hot one are different. To start a cold engine, a suction is switched on, which reduces air absorption and increases the percentage of gasoline in the fuel-air mixture.
- The chainsaw starts up and stalls, without gaining the necessary speed. You have to constantly work with a gas trigger, maintaining high revs.
- The engine stalls when working under load, does not develop optimal power.
Faults can be caused by both mechanical causes and problems associated with electrical equipment.
Reasons for malfunctioning
There can be several reasons for reducing power and reducing speed. We list some of them:
- Wrong ratio of oil to gasoline in fuel. If there is not enough oil, then the cylinder walls are not lubricated and scores appear. If there is an excess of oil, then in this case the engine does not gain power. Saw during operation is excessively smoke.
- Incorrect carburetor operation. This is due to incorrect adjustment. The working mixture comes in poor quality. The engine is choked with fuel, and the chainsaw stalls when you press the gas, or, conversely, gasoline is not supplied enough.
- Blown spark plug electrode. The motor runs intermittently. A strong vibration appears.
- The contact in the electrician of the instrument is broken. In this case, the saw does not start at all.
- The air filter is clogged. The engine does not develop power and stalls at idle.
- Clogged gasoline filter. Inadequate fuel intake in the carburetor.
- The exhaust system is clogged. In this case, the power drops to 40%.
- Depreciation of the cylinder-piston group. Insufficient compression does not allow to develop power. The engine is deformed.
Fuel filter cleaning
With insufficient fuel supply, the chainsaw stalls with gas. The reason may be a clogged fuel filter and a malfunctioning carburetor. How to check that a filter is to blame? To do this, you must partially disassemble the tool body in order to gain access to the carburetor. Disconnect the fuel hose from it and press the fuel pump several times. On modern saws, this is a transparent rubber hemisphere, which is pressed before starting the engine.
If gasoline intensively begins to splash out of the hose, then the filter is in order. If the fuel is reluctant, you need to change or clean the filter.
It is located inside the gas tank, and in order to get it, you need to remove the plastic protection, then use a flat screwdriver to pry off the rubber sleeve through which the fuel pipe passes. It must be removed carefully so as not to damage the rubber. Otherwise, it will leak after installation. In some chainsaws, the filter goes through the neck of the gas tank.
At the end of the fuel line installed in the tank is a fuel filter. It is usually clogged with tarry deposits found in gasoline and oil. The filter is pressed into the hose and removed by simple pulling. It must be washed in hot water with cleaning agents or replaced with a new one.
Air filter clogged
The main reason for the clogging of the air filter is the fine dust generated during sawing wood. The cutting of a raw tree is especially severe. Of all the causes of a deafening chainsaw, this is the most common. The exception is some models. For example, the “Calm” chainsaw stalls for various reasons, but not because of a clogged air filter. Because its carburetor is equipped with a compensator, which takes air if the filter does not cope.
Particles of wood dust penetrate under the body and are sucked in by a filter mounted on the carburetor. A clogged mesh creates air resistance, and it gets into the carburetor in a smaller amount.
In order to clean the air filter, it is necessary to dismantle the closing cover and separate it from the carburetor.
Before removing, brush off the sawdust or blow it with air. Then remove the filter so that debris does not enter the carburetor. At the time of cleaning it is necessary to close the carburetor with a cloth.
Then the filter must be purged with compressed air from the inside, and then installed in place.
No spark: ignition system problems
Usually, when they look for the reason why the chainsaw stalls, the first thing they look at is a spark on the spark plug. Often, the owners of the saws simply forget to change the candles on time. But it depends on her how stable and economical the tool will work. If the chainsaw is used intensively, then the candle needs to be changed once a season.
If no spark plug defects are detected, there is confidence in high-quality contact between the high-voltage wire and the spark plug cap, but there is no spark at the same time, then there is a malfunction in the electronic ignition unit. It is difficult for a person without an electrician education to understand anything there. This node is easier to swap whole.
External inspection of a candle
A visual inspection of the spark plug can tell a lot about the operation of the engine:
- The wet working part, which is wrapped in a cylinder, indicates a malfunction in the power system. The fuel mixture is too enriched. Carburetor adjustment required. Or the wrong ratio of oil and gasoline. The oil is poured more than the norm and it does not have time to burn out during the stroke of the piston. Carbon appears.You need to clean it with sandpaper. In no case do you need to ignite the candle with an acetylene or gasoline burner. After that, the inside of the candle may come off.
- Faint spark. To see the spark, you need to unscrew the candle. Then a high-voltage wire is connected to it , the candle is pressed with the metal part to the cylinder. Then you need to pull the starter, and at this time look at the electrodes of the candle. A weak, unstable spark can indicate poor contacts in connection with a high-voltage wire, incorrect gap between the electrodes. Different candles have this gap from 0.5 to 0.7 mm. As a result of the fact that the internal electrode gradually burns out during operation, the gap increases. To restore the distance, you need to knock the external electrode a little, or put a new candle.
- Depressurization of the candles. Sometimes you may notice a dark border between the candle insulator and the metal nut. This indicates that the metal part has moved away from the ceramics. With such a candle, the chainsaw stalls or works intermittently. This is because a spark pierces the cylinder through the body of the candle. Depressurization can occur with a cheap low-quality candle, or if at the time of installation, it was unduly tightened.
Carb adjustment
After you unscrew the candle and find that it is raw or it has soot on it, it's time to look at the carburetor. Its malfunction will lead to the fact that the tool is unstable at idle. Or the chainsaw stalls when the trigger is pulled.
The carburetor requires periodic adjustment. For this, manufacturers provided 3 screws. One of them regulates the maximum speed, the other minimum, and the third idle. What you need to do to adjust:
- Start the saw motor and warm it up to operating temperature. To do this, let him work for several minutes at minimum speed.
- The idle speed is adjusted in such a way as to find the middle position between when the chainsaw starts and dies, and the position when the chain starts to rotate when idle. At low speeds, the screw rotates clockwise.
- Make a trial cut of logs. If the chainsaw stalls when you press the gas, you need to adjust the needle of maximum speed (High) to adjust for maximum power. The chain rotation speed should not increase.
Carburetor work in winter
People working with chainsaws have repeatedly noticed that an inexpensive tool that works great in the summer loses its characteristics in the winter. For example, the “Partner” chainsaw working flawlessly in warm weather stalls with the onset of cold weather. What is the reason for this?
On saws of an expensive price category, the carburetor has two operating modes - winter and summer. Initially, the chainsaw is set for the summer. In order to transfer it to the cold operating mode, you need to open a special shutter. Then air will be sucked into the carburetor not from the street, but from the side of the hot cylinders, which will ensure stable operation in the cold.
However, this solution does not save from the problem of a cold start in winter.
Power System: Incorrect Fuel Mixture
Two-stroke engines are designed to operate on a mixture of gasoline with oil, which is needed to lubricate the cylinder-piston group. Lack of oil will quickly disable the tool and lead to overhaul.
In gasoline tools of different manufacturers, the ratio of oil to gasoline is 1:40 or 1:50. Under no circumstances should this proportion be violated. Filling with more oil than necessary will result in coking of the piston compression rings. They will slam tight in their grooves, and the motor will lose compression and power.
The only exception is the tool break-in mode. In this case, the mixture is made 1:25 and it is used for a short time, with a minimum load.
The signs of an excess of oil in gasoline are as follows: the chainsaw stalls, smokes profusely, does not develop power.
Conclusion
In addition to the above-mentioned malfunctions, which are easy to fix by yourself, there are wear on the cylinder-piston group and a clogged exhaust system. All this leads to a loss of power.
CPG repair - work for specialized centers. It is quite expensive, and in some cases it is easier to purchase a new tool. After all, a major overhaul indicates that the resource of the tool has already been exhausted.