Weak Spark On Chainsaw Reason

Faults in the cylinder-piston group

Cylinder and piston wear, scratches and seizures on their surface, wear of piston rings or crankshaft bearings. all these are very serious damages. As a result, they lead to a pressure drop in the cylinder. In this case, it will be very difficult to start the engine.

If there is compression, you will feel your finger sucking inward.

When you hit the gas

The sawing units are idling, but the saw stalls when the gas is pressed, because the load increases. Before use, the tool is warmed up by running the engine at idle for a minute. If this is neglected, the motor will stop after pressing the pedal. Other reasons could be:

  • Clogged or unregulated combustible fuel mixing assembly;
  • A clogged air filter does not provide the required air flow when the load increases;
  • A dirty gasoline filter does not allow the required amount of mixture to pass through;
  • Cylinder and piston wall rubbing.

Low octane fuel becomes the reason for brakes, because this circumstance does not allow the engine to reach the required power when the load increases.

No sparks chainsaw

Chainsaw won’t start no spark Description of all circumstances Cheap products from China

What to do

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

Fuel supply

After unscrewing the candle, a wet bloom is found on its surface. This indicates an excessive supply of gasoline into the combustion chamber. For this reason, the tool does not work or stalls, because the fuel does not ignite.

Weak Spark On Chainsaw Reason

Another inhibiting factor is a clogged breather. a small hole in the gas tank cap. It is cleaned with a needle, otherwise the Stihl MS 180 chainsaw will not start. To determine the incorrect fuel supply, follow the sequence:

  • Remove the candle;
  • 2 cubes of gasoline are poured into the hole of the candle with a syringe;
  • Put the ignition device in place and put on the cap of the high-voltage wire;
  • The lever is moved 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 crankcase, the integrity of the baffle in the pump when unscrewing the cover.

If a blue spark jumps from a distance of 2-3 mm, then everything is in order. If a spark occurs only at a distance of 0.5. 1 mm, it is most likely that there are problems with the ignition system. If there is no spark, check the high-voltage cable with a probe. Maybe a wire break has occurred in it.

Checking the ignition coil

To check the ignition coil, you need to pull the center wire from the coil from the distributor-breaker cover.

When rotating the starter, make sure there is a spark from the wire, by analogy with spark plug wires.

  • The appearance of a spark indicates that the ignition coil is working. In this case, the fault should be looked for in the distributor breaker.
  • If there is no spark from the wire, then the cause of the malfunction is hidden either in the ignition coil or in the low voltage circuit.

If there is a malfunction in the ignition coil, it should be replaced with a new one.

Checking the ignition distributor

If you suspect a breaker-distributor malfunction, you must carefully inspect its cover from the inside.

  • If the cap is ok, then just flush it with gasoline.,
  • If cracks are found, the cover will need to be replaced.
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The center carbon contact of the breaker is checked for "hanging" by moving it easily with your finger.

The rotor insulation of the interrupter-distributor is checked for breakdown as follows:

  • Place the central high-voltage wire with a gap of 5-8 mm from the rotor electrode,
  • After that, close-open the breaker contacts by hand (the ignition must be on).

The appearance of sparks in the gap indicates a malfunction of the rotor, which will need to be replaced.

Battery check

A clear sign of a problem with the battery is a dull and quiet horn. Also, in case of problems with the battery during the rotation of the starter, as a rule, the control lamps on the instrument panel go out. In this case, the reason for the absence of a spark may be poor contact on the terminals or a low battery.

  • If terminals are oxidized, they must be cleaned and tightened. In addition, graphite grease can be used to reliably protect the contacts from oxidation in the future.
  • If the battery is discharged, it must be charged with a charger.

For information on how to properly charge a car battery and maintain it, read our instructions for charging the battery.

Troubleshooting the ignition system

Malfunctions of the car’s ignition system are unpleasant in that any of them are always accompanied by serious interruptions in the operation of the engine or its complete stop. The main symptom of a malfunctioning ignition system is the complete absence or "weak" spark between the spark plug electrodes. What if there is no spark, and where to look for it? Read about this and not only in our material.

Most often, the spark disappears exactly at the moment when you need to go somewhere. In order not to push the car to the nearest car service, it is important to understand what the operation of the ignition system depends on, then the search for the missing spark will not cause any particular difficulties.

At the end of this article, see the instructions for finding a spark in the ignition system of VAZ cars.

And below we propose to get acquainted with the algorithm for finding the missing spark in the car ignition system.

Checking high voltage wires

Next, it is worth inspecting the high voltage wires: they must have a neat, not “tousled” appearance, without insulation violations, otherwise they will have to be replaced. If the wires are in order, then you can start looking for a spark.

We recommend starting the search for a spark with spark plug wires. To do this, remove the tip of the spark plug wire from the spark plug and bring it to the "ground" (the nearest metal unpainted part of the body or engine) at a distance of 5-8 mm, after which it is necessary to turn on the starter for a few seconds.

The rotation of the starter should be accompanied by an uninterrupted bright spark of white with a slight blue tint. If there is no spark, check the ignition coil. A purple, red or yellow spark indicates a malfunction in the ignition system.

It is also worth noting that the spark plugs themselves rarely fail all at the same time. If there is a "spark" in the spark plug wires, you can check any spark plug by unscrewing it from the cylinder head and putting the spark plug wire on it. With the metal part of the spark plug touch the "mass" of the car, and rotating the starter, make sure that there is or is not a spark on the spark plug electrodes.

It is necessary to change the spark plugs within the time frame established by the maintenance regulations for your car (usually every 15-25 thousand km).

You can find out more about the marking and glow number of spark plugs from our material at this link.

Why is there no spark on spark plugs?

There can be several reasons for the absence of a spark on a spark plug. The most common culprits for malfunctions are:

  • Accumulator battery;
  • High voltage wires;
  • Ignition coil;
  • Distributor;
  • Malfunctions in the low voltage circuit.
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Also, in the absence of a spark, special attention should be paid to checking the quality of contacts and electrical connections of the elements of the ignition system. You can check the status of the contacts by simply rubbing them with your hand.

Carefully inspect the wires and blocks of the ignition system. if you find dirt, oil or water on them, they must be wiped with a dry cloth. Then try to start the engine, it is possible that this time it will start.

Chainsaw outlet check.

One of the reasons that a chainsaw does not start well may be a clogged exhaust channel or its muffler. At the same time, a drop in power is noted in the process of sawing lumber and logs. Most often this occurs due to tarry deposits on the spark arrestor or muffler channel, which are formed during the combustion of a poor-quality mixture of gasoline and oil, which impede the removal of exhaust gases.

Resonator clogged with carbon deposits can cause poor starting of the gasoline saw.

Eliminate the cause of the poor start of the chainsaw, in this case, you can remove the accumulated combustion products. To do this, perform a number of manipulations:

  • Remove the muffler by unscrewing the screws;
  • Remove the cooling panel and gasket;
  • Remove the spark arrester;
  • Disassemble the resonator housing;
  • Wash all elements from carbon deposits with detergent;
  • Let them dry completely;
  • Collect everything in reverse order;

Searching for reasons why the chainsaw won’t start

Amateur and professional chainsaws are complex devices. The service life of their two-stroke engines, components and assemblies has its own limitations. For this reason, quite reliable and expensive tools, along with cheap Chinese units, periodically fail and refuse to start. The situation when the chainsaw does not start or stalls is not very pleasant and sometimes confuses the user. How to identify and correct a malfunction by returning the instrument to work.

  • Identification and elimination of obvious faults of the chainsaw.
  • Checking the spark on the spark plug and troubleshooting.
  • Determine the availability of fuel and its supply.
  • Checking the condition of the fuel and air filters.
  • Checking the breather and cleaning it.
  • Chainsaw outlet check.
  • What to do if the chainsaw won’t start further?

Identification and elimination of obvious faults of the chainsaw.

To determine the reason why the chainsaw does not start or stalls when starting, it is necessary to troubleshoot the tool. The essence of the procedure is to consistently inspect the condition and operation of the main working elements of the saw motor. At this stage, we check:

  • Spark plug present;
  • Fuel supply;
  • Filter status;
  • The operation of the breather of the stalling unit built into the fuel cap;
  • Discharge duct function.

To the content

Checking the condition of the fuel and air filters.

If everything is in order with the fuel quality, the chainsaw engine may not start due to clogged fuel and air filters. To diagnose these elements, it will be necessary to perform a number of manipulations associated with their dismantling.

For the fuel filter:

  • Disconnect the gasoline supply channel from the carburetor;
  • Pump up fuel.

If there is little or no pressure in the pipe, disconnect the filter. Before this, free the tank from the mixture and remove the filter element itself. Dismantling is done with a wire hook. A clogged replacement cartridge that causes a poor starting of the chainsaw engine can be cleaned, but it is best to replace it with a new one. When using the tool in dusty conditions, it should be cleaned on a regular basis.

A clogged air filter can cause the chainsaw engine to run erratically, making it stalling or difficult to start. Dust and dirt deposited on the adsorbent material impede the flow of air into the system, make the fuel mixture so rich that starting the tool will sometimes be difficult.

Checking the air filter is one of the first steps in finding the cause of a poor start.

Care should be taken when removing the air filter, as dust accumulated on the surface of the saw during operation can enter the carburetor. And this is fraught with more expensive repairs. After detaching the cartridge, thoroughly clean it from accumulated dirt and rinse it with the addition of detergent. Dry the element and place it in place just as carefully.

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Checking the breather and cleaning it.

The breather is another element, from the improper operation of which the chainsaw may not start or stall during the sawing process. This element is located on the fuel tank cap in the area of ​​the air hole. This is a kind of valve that does not allow gasoline to flow out and equalizes the air pressure required for the free flow of fuel into the carburetor.

If the breather is dirty, the working chainsaw stalls, and when started it refuses to start. The thing is that air stops flowing through the hole. As a result, a negative pressure (vacuum) is created inside the fuel tank, preventing the flow of gasoline to the carburetor.

Defining the problem is pretty straightforward. Disconnect the fuel hose from the carburetor and see what happens to the gasoline. If it flows out freely in a good trickle, then everything is in order with the breather. If it is absent or it flows weakly and intermittently, then the reason is identified. the breather is clogged with dirt. You can solve the problem by cleaning the air hole with a regular needle or a powerful jet of compressed air.

Checking the spark on the spark plug and troubleshooting.

The first step in looking for reasons why your gasoline saw won’t start is to check the spark on the spark plug. There are many factors that affect the performance of this element. However, the main ones at the initial stage of instrument troubleshooting are:

  • Incorrect carburetor adjustment;
  • The presence of more than it should be, the amount of oil in gasoline;
  • Clogged air filter.

All of them contribute to the formation of carbon deposits on the spark plug electrodes. In 50 cases out of 100, the saws do not start on a cold one due to the absence of a spark due to carbon deposits on the electrodes and their corrosion. As a result, the gap either decreases or increases.

Checking the spark plug with an idle chainsaw

Checking for a spark is fairly easy. This will require:

  • Remove the tip of the high-voltage wire;
  • Unscrew the candle;
  • Put the tip back on;
  • Lean the candle with a skirt against the cylinder;
  • Start with a starter.

If a good spark is observed between the electrodes at the time the chainsaw engine starts, then everything is in order with the ignition unit. If it is not there, then it is worth cleaning the element itself and checking the gap of the electrodes. If necessary, using a special probe, adjust the distance between the contacts.

There may be no spark on the spark plug for other reasons. Of the main faults affecting the poor start of the chainsaw and the unstable operation of the internal combustion engine at idle, from which the tool can stall, include the following:

  • Overflow of the spark plug channel with fuel;
  • Lack of contact between the high-voltage cradle and the tip of the candle;
  • Failure of the ignition unit.

How to start a cold chainsaw if the candle channel is constantly flooding with gasoline? To eliminate the problem while starting the tool, use the following algorithm:

  • Unscrew the candle with a special key;
  • Wipe it with a clean and dry cloth;
  • Dry for 20. 30 minutes;
  • Remove carbon deposits with a file and adjust the gap between the electrodes;
  • Drain the remaining fuel from the spark plug channel and dry it;
  • Collect everything and try to start the mechanism.

If there is no spark with poor contact of the high-voltage cradle with the spark plug tip, check the connection. The check can be done using a conventional tester. If a defect is found and it is eliminated, the chainsaw should start without any problems.

If the check showed that the contact is reliable, and the saw does not start further, look for the cause in the ignition unit. As a rule, a faulty unit cannot be repaired or restored. A complete replacement is required here.