Weak spark on the chainsaw cause

Outlet channels

After prolonged use, the exhaust channels of the chainsaw could coke, which causes opposition to the forward movement of the piston. Simply put, not removed gases slow down the engine.

How to fix:

• Remove the muffler of the chainsaw.
• Remove the gasket carefully.
• Dismantle the spark arrester.
• Disassemble the housing (if possible) of the resonator.
• Clean the parts using detergent solutions (kerosene, WD-40) and mechanically.
• Wipe, dry the nodes.
• Assemble the system back.

What to do if all else fails?

If the chainsaw still does not start, and it was not possible to identify the causes and remedies, then this is a reason for a visit to the service center. But if he is not nearby, then you can try to perform a number of other actions, all this at your own peril and risk.

What else could be the reasons for the malfunctions:

• Low compression ratio in the cylinders. if the compression rings are worn out or deformed, then there is an excessively large gap between them and the cylinder walls. Because of this, the fuel mixture does not burn, but seeps out.
• The carburetor is not tuned. it is difficult for an amateur to properly adjust the device, but it’s worth a try.
• Mechanical faults. if extraneous sounds were heard before the breakdown: grinding, clanging, ringing, then the internal parts of the engine are probably destroyed. It will be extremely difficult to do something without the experience of overhauling two-stroke engines.

Compression is measured using a device of the same name (compressometer). It is screwed in instead of the spark plug, after which you need to try to “start” the engine. The reading that appears on the dial will be the actual compression value. The nominal value will have to be found in the documentation for the engine.

If there is no compression meter, then we do this:

Checking acceleration

Smoothly press the accelerator and see how quickly the engine picks up speed from idle to maximum power. If the engine picks up speed slowly, it is necessary to loosen the L (low speed) screw by turning it slightly counterclockwise (no more than 1/8 of a turn).

Troubleshooting Algorithm

In all other cases, the search for ignition faults begins from the end and in order. Check the spark after each step.

• Change the old candle for a guaranteed working one.
• If the model has a removable candle cap, it is removed, the bare candle wire is shorted to ground with a gap, approximately like a candle. Pull on the starter. If there is a spark, the problem is in the cap. It is eliminated.
• Change the spark plug wire where it is possible to dismantle it from the source.
• Visually inspect the wires from the switch. Vibration, in case of contact with metal, can damage them. If there are places of friction, the wire is changed, even if there is no external damage to the insulation. You can use a tester or multimeter to check the wire.

This is where minor and easily fixable problems end. If the problem is not resolved, then the cause is more serious. Modern coils and ignition systems on most chainsaws are very reliable. They are designed to last even longer than the entire chainsaw. They do not have mechanical moving parts like the old cam systems. They are sufficiently insulated from clogging and moisture.

If, due to an accidental factory defect, an interturn short circuit occurs in the coil or the electronics fail, these parts cannot be repaired. Replacement with new ones will be required.

There is not an uncommon breakdown of mechanical properties. Due to wear or destruction of the crankshaft bearing, play appears on it. And then the magnetic rotor begins to touch the housing of the ignition system, inside which it rotates. This is a serious breakdown. You will need to “halve” (disassemble) the entire engine, replace the bearing, and put everything in place.

Check the chainsaw at idle again

Once we have adjusted the acceleration and maximum RPM, we check the engine idling again. We will understand that we have adjusted the carburetor correctly if:

• The chain does not move when idling
• Engine picks up speed
• The sound of a running engine resembles the sound of a four-stroke internal combustion engine

If at least one of these conditions is not met, the adjustment should be repeated (excluding the basic stage).

The reasons for the violation of the adjustment of the carburetor of the chainsaw:

• Heavy wear on the engine (pistons). In this case, more care must be taken to repair the engine, however adjusting the carburetor may improve the saw’s functionality for a period of time.
• Blockage in the carburetor due to damage to the air filter, the use of poor quality gasoline and the formation of scale In such a situation, in addition to adjusting the carburetor, you will also need to flush it.
• Strong vibration of the saw or damage to the protective cover. This happens extremely rarely, but there are still cases.

Signs that indicate the need to adjust the chainsaw carburetor:

• The engine either does not start, or it starts and immediately stalls. This is due to the use of a poor fuel mixture.
• Significant increase in fuel consumption and emissions. An increase in the amount of exhaust gases indicates that the fuel is not completely combusted. The reason for this may be oversaturation with fuel.

The carburetor adjustment scheme for different models of chainsaws is different and is described in the instruction manual. However, the general principle remains the same: it is necessary to change the quantity and quality of the fuel mixture supplied to the engine cylinder.

Weak spark reasons

A weak spark on a chainsaw is a relative concept. Most often, a spark is either present and the ignition is working properly, or it is not there at all. In modern chainsaws with electronic ignition, the spark visually seems to be weak.

On older models with a mechanical cam interrupter, the spark was large, with a strong blue color. On modern models with electronics, it is noticeably smaller and paler, more often yellowish. Therefore, when you need to make sure of its presence, it is better to do it in the shade. In direct sunlight, it is almost invisible.

IF YOUR SAW HAS A FAILURE THAT IS NOT SPECIFIED IN THIS ARTICLE, PLEASE CONTACT YOUR SERVICE CENTER FOR CONSULTATION!

In this article, we will consider the main causes of chainsaw malfunctions, how to diagnose and eliminate them.

This material will highlight the following points:

Battery check

A clear sign of a problem with the battery is a dull and quiet horn signal. 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 at the terminals or a low battery.

• If the terminals are oxidized, they must be stripped and tightened securely. In addition, you can use graphite grease, which reliably protects 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.

Quick Tip #21 Bad Ground on Coil / Magneto, Causes Weak or No Spark

Checking the ignition coil

To check the ignition coil, pull the central 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 properly. In this case, the malfunction should be looked for in the breaker-distributor.
• 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.

Why is there no spark on spark plugs?

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

• Accumulator battery;
• High voltage wires;
• Ignition coil;
• Distributor;
• Malfunctions in the low voltage circuit.

Also, in the absence of a spark, special attention should be paid to checking the quality of the 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. After that, try to start the engine, it is possible that this time it will start.

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 video 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 the ignition switch-distributor

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

• If the cap is ok, then just flush it with gasoline.,
• If cracked, the cover will need to be replaced.

The center carbon contact of the breaker is checked for “hang-up” 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 (while the ignition must be on).

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

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, you need to 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, you need 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 while 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 learn more about the marking and glow plug number of spark plugs from our material at this link.

Checking the low voltage circuit

A 12V test lamp up to 3W can be used to test the low voltage circuit. The lamp is connected on one side to the low voltage terminal of the breaker, and on the other to the vehicle ground.

After that, you need to manually close the contacts of the breaker-distributor and turn on the ignition. With a good low voltage circuit, the control lamp should glow when the contacts open, and when they close, go out.

If the lamp does not light up when the contacts are opened, it means that the malfunction is hidden either in the low voltage wires or in the primary winding of the ignition coil.

The constant glow of the lamp, in any position of the contacts, indicates one of three reasons for the malfunction:

• Strong oxidation of the breaker contacts;
• Broken wiring leading from the breaker terminal to the lever;
• Broken wiring connecting the moving disc of the breaker to the housing.

If the cause of the malfunction turned out to be in the oxidized contacts, then they must be cleaned, after which the gap should be adjusted.

Ignition faults

How to make sure there is really no spark

To make sure there is a spark on the chainsaw or not, you need to follow a simple procedure:

• Removing the top cover on the case.
• Carefully, with a grip at the very bottom, so as not to tear off the candle wire, the cap is removed from the candle.
• With a 19 socket wrench included in the kit, the candle is unscrewed counterclockwise.
• The cap is put on in place, on the candle.
• The thread or nut of the candle is “shorted to ground”, that is, pressed against the metal cylinder head. To ensure reliable contact, the candle is pressed against the cylinder with electric pliers, a screwdriver with insulated handles, or with a hand with dielectric gloves. You should not do this with your bare hand. If the cap breaks down, you can get a painful shock from a high-voltage discharge (up to 40,000 V at a low current strength of up to 80 milliamperes).

Place the chainsaw on the ground, press it with your foot on the ground, and lightly pull on the starter cord. At this time, it will be seen whether there is a spark or not.

Ignition adjustment

As we have already noted, you can adjust the ignition system both in the workshop and at home. To do this, you need ordinary wrenches, a screwdriver and a 0.4 mm dipstick (you can make a dipstick with your own hands from scrap materials. plain copier paper, a plastic bottle, etc.).

Chainsaw gap setting overview

Overview of how to replace the reel on a chainsaw

Constructive components

All gasoline two-stroke engines have a similar operating principle, and therefore the ignition system in them has a typical structure and device.

Semyon Starodubtsev, 54 years old, Krasnodar

“I was cleaning the garden in the spring, the chainsaw began to sneeze, and then it completely stalled. I looked at the candle. it was completely wet, it was evidently flooding. I cleaned the carburetor, changed the plug. it won’t start. Looked. there is no spark. I disassembled the ignition and found the reason. the high-voltage cable was completely melted. Why this happened. I still don’t understand. I changed the cable with the module. now everything works fine. “

Chainsaw ignition

A chainsaw, like any device powered by an internal combustion engine, has an ignition system. It is responsible for igniting the fuel-air mixture in the engine cylinder. This occurs through the delivery of an electrical discharge that breaks through the space between the spark plug electrodes.

It is clear that without fuel ignition, no engine will start and will not work. However, the problem is not only this: the quality of the chainsaw depends on how accurately the ignition is set. In other words, fuel ignites on time or at the wrong time. Therefore, the chainsaw with knocked down settings needs to be repaired. The troubleshooting can be entrusted to an experienced mechanic, but you can repair the ignition of the chainsaw with your own hands.

Important: new chainsaws are supplied with adjusted ignition, there is no need to disassemble and assemble the tool immediately after purchase.

Some Chinese chainsaws come with low-quality spark plugs. it may make sense to have several spark plugs included. In our review, we will introduce you to the device and how the ignition system works, its main problems and how to fix them.