The Main Reasons Why The Stihl Chainsaw Does Not Start And How To Eliminate Them.

Light and compact model of the tool is used for domestic purposes, but, despite the optimized performance, sometimes Stihl chainsaw does not start. The problems are manifested in the fact that the engine turns on and stalls are unstable, cannot develop the necessary power, or suddenly gains high speed.

Why not start a chainsaw Stihl.

For a preliminary diagnosis of the causes, check the operation of the fuel pump, the appearance of the spark plug, the flow of fuel, the functionality of the carburetor and the condition of the filter. Pay attention to the performance of cylinders, pistons, muffler, crankshaft bearings. After preventive measures try to run a chainsaw. Insufficient lubrication of rubbing parts also becomes a factor of poor performance.

No spark.

Spark on the spark plug is being tested. The functioning of the element is affected by various factors. When testing the mechanism

The reasons are revealed:

  • insufficient adjustment of the carburetor;
  • large oil in the composition of gasoline;
  • clogged fuel and air filters.

Because of the work in such conditions on the contacts of the candles accumulated carbon deposits. The subsequent corrosion of the conductors is the reason that there is no spark in half of the faults. It is so because of the gap between the modular contacts changes.

To check the spark, do the following:

  • tip of high voltage cable is removed;
  • the candle is twisted off;
  • tip put in place;
  • candle leaning wide end to the cylinder;
  • start the starter.

If during start-up between the electrodes, a bright spark appears, resembling a flash of lightning, then the ignition unit is operational. In the absence of a flash, clean the entire element and expose the gap between the conductors. Sometimes there is no gap between the flywheel and the ignition coil. At friction of a flywheel on its appearance, scratches are visible.

Ignition Coil Malfunction.

The module or the coil does not understand. Its suitability is difficult to identify without testing devices. Modern ignition systems are durable, lightweight and small in size. They are characterized by almost trouble-free functionality. Problems with the failure of the chainsaw due to the ignition coil can be fixed by yourself.
They test the lead wires for damage (including internal), which are caused by vibration, leading to friction. If no cracks are detected, then the ignition coil needs to be replaced. Sometimes a weak, subtle flash when the saw is heated indicates a module malfunction. It is due to an increase in coil temperature, which leads to an increase in the resistance of the transistor.
The peculiarity is that at the beginning of work, the spark may appear, but after prolonged use, it becomes dull and disappears. New ignition coils in the home workshop do not repair, because of change for valuable items.

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Fuel supply.

After twisting the candle, a wet coating is detected on its surface. It indicates an excessive supply of gasoline to the combustion chamber. For this reason, the tool does not work or stalls, as the fuel does not ignite.
Another inhibitory factor is clogging of the breather. a small hole in the cap of the gasoline tank. It is cleaned with a needle. Otherwise, the Stihl MS 180 chainsaw will not start.

To determine the wrong fuel supply spend the following steps:

  • remove the candle;
  • two cubes of gasoline are poured into the hole of the candle with a syringe;
  • put a device to ignite in place and put on a high-voltage wire cap;
  • the lever is transferred to the hot start position;
  • pull the starter handle a couple of times.

If the tool starts up and immediately stalls, then the fuel line is tested further. Check the gasoline filter, splash from the engine crankcase, the integrity of the septum in the pump when unscrewing the cover.

Crankshaft bearing failure.

With bearing defects, there is a weak play. To identify it, the Stihl MS 180 saw flywheel staggering from one side to the other. The movement suggests that the flywheel is shifted towards the electrodes by its magnets, with the result that there is no spark. To remove the mechanism, remove the cutting element, remove the filter cover and clutch. For the crankshaft stopper, remove the manual starter cover and tighten the two bolts.
The clutch is unscrewed with a wrench in a clockwise direction. Remove the drum with an asterisk, change the old clutch and tighten it until it stops. Crankshaft stop so as not to break the starter. Going mechanism in reverse order. To tighten the brake lever is tilted forward, the tool is turned on, then removed from the brake.
Less frequently, bearings with defects are detected (the diameter of the holes is increased in the holder). To determine dismantled and measured using a micrometre. On the broken bearings shows a regular knock. In this case, urgent repairs are required, since the piston group and the cylinder will be damaged if the crankshaft is damaged.

Fills the spark plug.

In this case, the spark is not able to ignite the fuel, which in large quantities enters the furnace for burning the combustible mixture. If the candle fills, the carburetor is faulty, or the cold engine starts up incorrectly. Carry out purging the engine. The procedure is performed with the ignition off and away from an open flame.

To ensure the ignition of the fuel at the time of launch, clean the mechanism:

  • unscrew the candle, wipe dry, dry for half an hour;
  • a large layer of soot is removed with a needle file;
  • between the contacts regulate the gap;
  • the instrument is turned upside down and gasoline is drained;
  • in this position, the starter is pulled several times (to remove the remaining fuel);
  • reassemble in the reverse order.

Chainsaw Stihl stalls: causes.

If the tool is turned off immediately after the start-up, it means that some device or part has failed. To determine the cause, test the mechanism independently or in service workshops.

Sometimes the reason that the mechanism starts badly is improper maintenance of the saw:

  • insufficient gasoline volume;
  • poorly prepared fuel mixture;
  • poor lubrication quality;
  • silencer clogged with combustion products;
  • unregulated carburetor;
  • air filter obstruction;
  • piston or cylinder failure.

When you press the gas.

The sawing units are idling, but the chain saw stalls when the gas is pressed, as the load increases. The tool is heated before use, driving the engine at idle for a minute.

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If this is neglected, the motor stops after pressing the pedal. Other reasons may be:

  • a clogged or unregulated combustible fuel mixing unit;
  • a clogged air filter does not give the desired air flow with increasing load;
  • a dirty gasoline filter does not allow the required amount of the mixture;
  • rubs the wall of the cylinder and piston.

The low octane number of fuel causes a break since this circumstance does not allow the motor to achieve the required power with increasing load.

At idle.

Violation of the functionality of the fuel assembly system leads to air leakage. In this case, the unit stalls at idle and does not keep their number. The additional leakage reduces the air pulse to the fuel pump and passes through the diaphragm or crankshaft oil seals. The diagnosis makes vacuum gauge.

The engine stops working for cold due to other reasons:

  • the candle channel contains an excess amount of combustible mixture;
  • between the tip of the candle and the high-voltage cradle the clearance is not adjusted;
  • power supply failure

Check the seals, pouring gasoline into the crankcase. The leakage is visible visually. It means that the engine does not work at idle speed, and at high frequency, leaky seals will lead to jamming of the bearings. In the case of the flow of elements, they are replaced with new ones, and they are sealed.

At full speed.

Sometimes the engine stalls after normal operation.

To establish the cause, pay attention to the surrounding circumstances:

  1. Motor stalls in the middle of work for no apparent reason. The starter is stationary and does not rotate. So, the tool is stuck and requires urgent repair.
  2. In the period of normal operation, the power reduces in a short time, and the engine stops, the cylinders are overheated. The situation suggests the occurrence of air suction under the rubber pipe between the carburetor cylinder, possibly due to a gap. Air depletes fuel, requires replacement of the pipe.

Not gaining momentum.

Many systems of the mechanism are involved in the launch, so the loss of revolutions of the Stihl chainsaw after idling can be a consequence of various factors.

Certain idle operation and interruptions in the motor under load may occur for the following reasons:

  • engine resource development;
  • wear, deformation and corrosion of the piston group;
  • malfunction of the ignition coil or spark;
  • unbalance carburetor screws.

If the tool does not develop momentum, then the conductivity of the hole in the fuel tank cap is broken. The occurrence of a vacuum does not give the required amount of fuel, because the engine does not pick up the required power. Turns decrease at carbon accumulation in the muffler, removal of gases from combustion is difficult.

Do not lose momentum.

The tool quickly goes to the maximum number of revolutions, and the power is not reduced.

This situation is due to the fact that:

  • the throttle valve does not work due to the weakening of the spring or the traction element;
  • periodically fails including a toggle switch;
  • no corkscrew on the throttle axis;
  • clogged carburetor;
  • The fuel hose and gasoline filter are not functioning properly.

What to do?

The power tool is operated according to the manufacturer’s instructions. Only after checking the tension of the chain unit starts. At the same time, the filling of tanks with a combustible mixture and oil is controlled, the device is securely fixed in the hands. If the mechanism refuses to work when all the rules follow, the Stihl chainsaw is repaired.

How to start a chainsaw Stihl: instructions.

The manufacturer of the instrument took all measures and developed a manual, thanks to which the mechanism is conveniently launched.

The user will protect himself from injury if he performs the proposed frequency of actions:

  1. The ignition is turned on, and the engine handle is placed in the lower position. A carburetor flap blocks the flow of atmosphere from the air filter. To properly start a chainsaw, the throttle membrane must be open to enrich the combustible mixture.
  2. The lever is set to the start gas position. The starter twitches several times before the first spark. If the flash passes, the tool is ready to run. The mechanism works at high speeds due to the closed throttle membrane. The gas is pressed, and the rhinestone is released to translate it into the regulation of idling. The number of revolutions quickly normalized.
  3. On the Stihl MC standard equipment, no extras are provided for starting a chainsaw in a lightweight version.
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Idling adjustment.

Before adjustment, carry out maintenance of the tool.

So that the idle adjustment is effective, they do the following:

  • cleaning the carburetor;
  • washing the engine;
  • cleaning the air filter;
  • warming up the motor.

To adjust the operation of the mechanism at idle, use the appropriate adjustment screw.

Its rotation depends on the desired setting:

  1. With the standard adjustment, the screw is turned against the hand of the watch to the position when it will turn tight. After that make two circles in the direction of the arrow.
  2. If the saw is running at low speed, the screw is turned clockwise until the chain begins to move. Then make a half circle in the opposite direction.
  3. At high frequency, the regulator is turned against the clock hand until the chain stops. After that, the rotation continues for another half a turn in the same direction.

Adjust the idle work will not work if there is air leakage into the engine through the gasket, acceleration pump, oil seals or for another reason.

Ignition setting.

Gasoline engines are equipped with an ignition system, through which fuel ignites. The time of occurrence of the flash affects the operation of the motor. With mass production in the factory, the adjustment of the ignition of the chainsaw is not made. On the corresponding rotating elements, tags are set, which are combined when setting up. Incorrect adjustment leads to the fact that the machine starts and stalls.
Before adjustment, check the dryness of the spark plug and the performance of the ignition circuit. The voltage supply cable to the candle is brought to the cylinder with a small gap, and the starter is started. If there is no flash, test the cable with a probe. Then check the serviceability of the wire to the disconnecting button.
If the cables are undamaged, check the ignition coil. It is done by a unique tester to ring the device. In this case, the indicators on the device must coincide with the technical characteristics of the coil, which are prescribed in the instructions for use. If inconsistencies are identified, the ignition unit changes to a healthy device.
The coil can become unusable due to vibration when the tool drops or bumps, so you need to work carefully.

Replacing crankshaft shaft bearings.

To begin, measure the compression, if it is not, then the reason lies in the failure of the piston group.
The required pressure in the cylinder should be 8 atm if it is lower, then the cylinder and piston, rings, crankshaft bearings may have worn out.

To find out the state of the piston system, you need to completely disassemble the saw and remove all the main components of the mechanism:

  • remove the headset, remove the cover on the tire;
  • remove the tire guide and tool chain with a wrench from the kit;
  • remove the air filter, remove the spark plug;
  • in place of the candles attach piston stopper for fixing the crankshaft;
  • remove the clutch, then access to the clutch system.

Rings with bearings inspect, identify defects. The replacement can be carried out independently, which will require the skill of repair, or carry the tool to a specialized workshop. The assembly is done in the reverse order.