The Chainsaw Won’T Start

Checking the spark plug and the gap between the coil and the magneto

The spark plug is the most important part that ignites the fuel mixture entering the cylinder chamber. If the candle has served its purpose, then it will give out a weak spark or not at all. You can check this in the following way:

  • Unscrew the spark plug
  • Put it on a cylinder by connecting it to a candlestick
  • Switch on ignition
  • Pull the starter handle

If a spark occurs constantly, then this indicates the serviceability of the candle. over, not only the candle is in good order, but also the ignition system. the coil and the high-voltage wire. If a spark occurs on the candle, but intermittently (intermittently), then such a part must be replaced. First you need to check the gap between the contacts. The gap should be between 0.5 and 1 mm.

For each model of a chainsaw, manufacturers indicate the recommended gap size, so you need to use a reference book. You can measure the gap with a special probe or a sheet of paper folded several times.

The absence of a spark on the spark plug indicates a malfunction of the ignition system, therefore, before replacing a part, you should make sure that the ignition coil and high-voltage wire are in good working order. The chainsaw may not start due to clogged spark plug electrodes. The presence of black carbon on the candle or wet electrodes. all this may indicate the following malfunctions:

  • Black carbon. Chainsaw carburetor not adjusted correctly. The mixture entering the cylinder contains a lot of fuel and little air. You can fix the malfunction by cleaning the carbon deposits on the spark plug electrodes, followed by adjusting the carburetor
  • If the candle is wet (it floods), then this may indicate the following. either the ignition system is faulty (including the spark plug itself), or an excess amount of fuel enters the cylinder, thereby filling the candle. First you need to make sure that the spark plug gives a good spark, and only then adjust the carburetor. It is not recommended to dry a wet candle by calcining, so it should be wiped dry and then allowed to dry in the sun
  • If the spark plug has red or pink carbon deposits on the electrodes, then this indicates that the gasoline used contains a large amount of additives. Typically, this effect is produced by AI-95 and higher gasoline, an increase in the octane number in which is achieved by adding additives

When the candle is brown (brick-colored), this indicates not only a properly adjusted chainsaw carburetor, but also that the ignition system is working properly. If a new spark plug is used, which, when checked, produces a weak spark (or there is no spark at all), then this is a sign of a malfunctioning ignition coil. The coil must be replaced together with the high-voltage wire.

Doesn’t start on cold and hot main reasons

If there is a spark on the chainsaw, but the tool does not start to cold, then the reason lies directly in the absence of compression. Measure the amount of compression on the engine to verify this problem. If the compression value is not lower than 8 atmospheres, then everything is in order. If not, then the engine has worked its way out and needs to be replaced by the CPG. When metal parts are cold, they taper, thereby reducing compression. To start the chainsaw on a cold one with low engine compression, follow these steps:

  • Pull the starter handle until the internal parts warm up due to friction
  • When parts are warmed up, compression will increase, so the engine will start
  • It is recommended to carry out these manipulations in the warm season, since it is almost impossible to start a chainsaw in winter with low compression.

It should be noted that it is very harmful to work with a tool with low compression. In addition to low performance, such operation will lead to permanent damage to the chainsaw engine.

Another situation is when the chainsaw does not start hot. This is primarily due to flooding of the engine. If it starts well on a cold chainsaw, but when there is a break after work, and there are difficulties with starting, then it is necessary to start without closing the air damper. The damper must be fully open (air supplied) to start the engine hot. If you can’t start the chainsaw, then you need to half-close the choke. Try to start the engine, and as soon as it starts, you can open the throttle completely.

If you cannot start a heated chainsaw engine, then proceed as follows:

  • Loosen the idle screw in a clockwise direction by орота a turn.
  • By increasing the number of revolutions, the process of starting the motor is simplified
  • Start the engine with the choke half open
  • After starting the engine, return the idle screw to the opposite position if the chain moves at idle
The Chainsaw Won'T Start

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Filling the spark plug may be due to a malfunction of the ignition module, as well as a large gap between the coil and the magneto. If the reason for the inability to start the engine of the chainsaw is in the carburetor, then it should be correctly adjusted as soon as possible.

After winter, I can not start the chainsaw, what can you tell me

If the chainsaw is not used in winter or summer, then with the onset of spring, when it becomes necessary to harvest firewood, a malfunction is often observed in the form of the inability to start the engine of the tool. The reasons may be different, but the first step is to check the presence of gasoline in the tank. If the chainsaw has not been used for a long time, but fuel remains in the tank, then the difficulties in starting a two-stroke engine are associated with the cause of stagnation of fuel.

If the fuel in the tank has not been drained before storage, then there is a high probability that a plug has formed in the carburetor. You will need to disassemble the carburetor and clean it. In order not to resort to these steps, you can do the following:

  • Unscrew the spark plug and inspect it. If it is dry and has the correct brown color, then no fuel is being supplied to the cylinder.
  • 20 grams of the fuel mixture is drawn into a syringe and sprayed into the cylinder
  • The spark plug is twisted and the engine is started
  • If the ignition system is working properly, the chainsaw will start

When the engine is started, the resulting plug in the carburetor will break through and the engine will run normally. If the engine starts and stalls on a chainsaw, then the procedure for adding fuel to the cylinder should be repeated several times. If the attempts end unsuccessfully, then you need to clean the carburetor, but first check the serviceability of the fuel and air filters, the ignition module and clean the exhaust channel (muffler).

Difficulties with starting a chainsaw cannot be ruled out due to such reasons:

  • Damping the electrodes of the candle
  • Oxidation of the contacts of the wires of the ignition module
  • Damage to the insulation of the high-voltage wire
  • Failure of the ignition coil
  • The need to adjust the carburetor

Difficulties with starting chainsaws arise sooner or later. It all depends not only on the quality of the tool and its price, but also on the features of the care, operation and storage of the tool. With proper care and storage of the tool, you will never have problems starting the engine of your chainsaw.

Is there fuel in the tank and what is its quality

Checking the presence of fuel in the tank is the first thing to start diagnostics with. Even if visually there is still fuel in the tank, make sure that the fuel line is lowered into it. If the fuel in the tank is at the bottom, then this is the main reason that it is impossible to start the engine. After adding fuel to the tank, it is necessary to pump the system, and only then carry out a test run of the engine.

If there is enough fuel in the tank, make sure that the supply hose inside the tank is not detached. On some models of chainsaws, such a malfunction is a "disease". If the tank is full, this does not mean at all that the breakdown is not related to the fuel system. Check the quality of the fuel (oil and gasoline). Gasoline for chainsaws is used mainly of the AI-92 brand. As oil, you need to use only a special two-stroke, but not an engine oil or even working off.

The prepared fuel mixture cannot be stored for more than 2 weeks, as the mixture begins to lose its properties, which negatively affects not only the operation of the engine, but also its starting. How does a poor-quality mixture affect engine starting, you ask? Everything is very simple, with long-term storage of the mixture, oil precipitates, which leads to clogging of the channels and jets of the carburetor.

The instructions for each brand of chainsaw indicate recommendations on the ratio in which gasoline and oil should be diluted. It is this recommendation that should be followed when preparing a mixture for a two-stroke engine of a chainsaw, otherwise it will significantly reduce the life of your tool.

Fuel and air filters. checking their serviceability

If the fuel or air filter is clogged, the chainsaw will also not be able to start. First you need to check the health of the air filter, which is located in a plastic case. Chainsaw air filter is very often clogged, therefore it is recommended to clean it before use. You will need to use a compressor for cleaning. If the air filter on the chainsaw is clogged with sawdust and shavings, then the engine will not start hot. Air does not enter the carburetor, so only excess fuel is supplied to the cylinder, which causes the spark plug to flood.

The case of a clogged air filter on a chainsaw is very interesting. If it is clogged, it usually starts up on a cold chainsaw, but as soon as the air damper opens to supply air, the engine immediately stalls after warming up. A hot chainsaw with a clogged filter will not start at all, or it will start and immediately stall. When diagnosing the air filter, you need to pay attention to the damper, through which the air supply is limited. Make sure the shutter moves freely when you push the lever to close and open.

  • If the damper does not close, then the attempt to start the chainsaw on a cold one is unsuccessful.
  • A similar situation is when the chainsaw is hot. If the engine starts up cold, but stalls when warming up, then this may be due to the fact that the damper is stuck in the closed position
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As you can see, not only the start of the chainsaw engine depends on the serviceability of the air filter and the damper, but also its proper operation.

In addition to the air filter, the cleaning element, which is responsible for cleaning the fuel mixture, can also become clogged. This filter is located in the chain saw tank and prevents small grains of sand from entering the carburetor. Like the air filter, the fuel cleaner also needs to be cleaned. Cleaning is done by replacing the old filter with a new one. The service life of this element depends on various factors, and first of all, on the quality of the gasoline and oil used. If you pour fuel into the tank in windy weather, then the probability of sand grains entering the tank is 100%.

Depending on the model of the chainsaw, the principle of replacing the fuel filter may differ. However, even a beginner can cope with this procedure, since it is not difficult, and only requires adherence to the sequence of actions.

If the chainsaw won’t start anyway, what to do

The above are the main reasons why the chainsaw does not start. over, this applies to tools of different brands Stihl, Husqvarna, Partner, Makita, Champion and others. Chainsaws Friendship have a different principle of operation, but in general, the search for a malfunction should begin with the ignition system, or rather, inspect the condition of the spark plug electrodes. If the manipulations carried out do not help to obtain the desired result, then it is necessary to resort to more serious actions. This means that you need to follow these steps:

  • Check the serviceability of the carburetor and adjust it
  • Measure the amount of compression of the engine, and then make an appropriate conclusion about its serviceability
  • Compression in the crankcase is checked

Checking the compression in the cylinder allows you to assess the condition and serviceability of the CPG. To measure compression, you need a compression meter. It is screwed into the spark plug hole, after which the starter handle is pulled. The compressor shows the corresponding cylinder pressure. This value should be at the level of 8-12 atmospheres.

If the pressure is significantly lower, then this is a direct sign of a device malfunction. In case of malfunction, the cylinder-piston group is replaced with a new one. When installing a new CPG, it is necessary to carefully treat all parts with oil so that chips and scuffs do not form at the time of engine start.

If there is no compression in the crankcase, then the chainsaw will also not start. The reason for the decrease in the pressure in the crankcase is the gasket, or rather its damage. This gasket is placed between the cylinder and the crankcase and, to make sure it is working properly, the following manipulations should be performed:

  • Disconnect the fuel line from the tank
  • Lower the tube into a container with a prepared mixture of gasoline and oil
  • Start the chainsaw engine
  • If the engine starts and fuel is sucked in, then this indicates the serviceability of the gasket.

If the fuel is not sucked in, then the crankcase gasket needs to be replaced.

The carburetor is the most important and most difficult part of a chainsaw. If all of the above steps did not help to get a positive result, then this indicates that the carburetor is faulty. The main malfunction of the carburetor is the clogging of its channels and jets. Membranes and other elements fail less often. In any case, you will need to disassemble the chainsaw carburetor, clean it and replace the failed parts.

As you can see, there are enough reasons why the chainsaw does not start. To find out what exactly happened in your case, you need to remember the symptoms the day before. Perhaps before the chainsaw stopped starting, engine malfunctions were observed, power and performance decreased, and other breakdowns were also appropriate. Based on these technical symptoms, it is necessary to begin the search. If you don’t know where to start, then the diagnostics should be carried out in order, as described in the material.

Engine jammed

Quite often there is a situation when the saw worked and stalled abruptly, the cause of which was the engine jamming, which in turn occurred as a result of a broken piston skirt, destruction of the crankshaft bearing, protrusion of the cork ring of the piston pin or fracture of the piston ring.

A jammed engine can be easily identified by pulling on the starter cord. In the case when the starter does not turn, most likely, it has jammed, and further repairs are possible only at the service center.

Malfunctions in the ignition system

If, when inspecting the spark plug, it is found that it is wet and sparking on the contacts does not occur, this means that the problem should be looked for in the ignition system, inspect the coil, check the gap between the flywheel and the coil contacts. You can also check how tightly the cap of the high-voltage wire sits on the candle, and the candle itself. Try to replace it with a new one.

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Violation of the sequence of actions when starting on a cold

If a new chainsaw does not start on a cold one, then the reason may be in the wrong engine starting sequence. As a rule, each manufacturer in the instructions for the chainsaw indicates the procedure for starting the chainsaw on a cold one. Basically, it is similar for all two-stroke internal combustion engines that are installed on chainsaws, and represents the following procedure.

  • Closing the air damper (necessary to enrich the fuel at start-up).
  • Fuel suction using a special primer for this (on some models of chainsaws, the primer is not provided by the design, and therefore this item is absent for them).
  • Turning on the ignition (if you forget about this, then you can mistakenly consider the instrument to be faulty).
  • Carry out several movements of the starter, before the first "flash" of the engine (it is important not to miss this moment, otherwise it is possible to "flood" the engine).
  • Set the air damper to the open position.
  • Start the chainsaw engine.

Ignition coil

The reason that a new chainsaw does not start, or does not start well, may be the ignition coil. Modern chainsaws are equipped with electronic ignition coils. This part cannot be repaired, and, as a rule, if there is a defect, it changes completely.

Chainsaw does not start well when cold. Chainsaw stalled and won’t start

If the tool stalled and does not start, first check the presence of fuel in the tank. Oddly enough it sounds, but many people forget about it and when a similar situation arises, they immediately try to repair the instrument, which can lead to serious damage.

In a situation where the saw has stalled, and there is still gas in the tank, you need to evaluate how the saw has worked up to this point. Maybe during work at the last moment there was an extraneous sound, rattling, ringing, power loss, or the instrument stopped abruptly. All this will allow a preliminary assessment of the situation.

Floods the candle

In the people, the phenomenon in which a spark cannot ignite a large amount of fuel is usually called candle flooding. The cause of the malfunction lies in the carburetor, or in improper cold start. If a malfunction is detected, first you need to "purge" the engine.

Defective crankshaft bearings

With a defect in the crankshaft bearings, a slight backlash is observed on it. You can check for backlash by shaking the flywheel of the Stihl 180 chainsaw from side to side. If there is a backlash, then, under the action of its magnets, the flywheel is attracted to the contacts of the ignition coil, since the backlash on the bearings allows it to do this and as a result the spark disappears.

Defective spark plug

The first thing to do is to check the performance of the candle.

This is pretty easy to do. The candle is inserted into the cap of the high-voltage wire and pressed against the engine cylinder, after which the starter moves several times, if there is no spark between the electrodes of the spark plug, then it is faulty or the ignition module is faulty.

In order to know for sure that the problem is in the spark plug, it is necessary to check the known good one in the same way. If, as a result of the check, a spark appears, then the problem has been found and to eliminate the malfunction we replace the spark plug with a new one.

For what reasons the Stihl MS 180 chainsaw will not start

The Stihl MS 180 chainsaw is considered one of the most reliable tools used in gardening. But with any technique, there are situations when it does not start for some reason. Let’s look at the main malfunctions due to which the Stihl 180 will not start or start poorly and how to fix these malfunctions.

Fuel line diagnostics

Typically, the diagnosis of the fuel supply system begins with checking the condition of the fuel filter. To do this, unscrew the tank cap and, using an aluminum wire bent at the end, remove the fuel hose from the tank, with a filter at the end.

Having taken out and dismantled the filter, you can try to blow into it, if air does not flow, then the problem has been found. If everything is in order, then you need to check the system for clogging.

To check the fuel supply hose, you must disconnect it in the place where it connects to the carburetor, and then blow into it. The clogged hose can be mechanically cleaned, if this is not possible, replace with a new one.

In the event that the supply hose and the fuel filter are normal, and the fuel supply is not observed, the reason may be hidden in a malfunction of the air pulse to the fuel pump.

There is no spark on the Stihl 180 chainsaw

The main malfunction due to which the stihl ms 180 chainsaw does not start may be the absence of a spark between the electrodes on the spark plug. Symptoms of this malfunction can be detected by unscrewing the plug and inspecting. Having discovered during inspection that the spark plug is wet, it is necessary to start looking for the reason for the absence of a spark on the spark plug.