How to adjust the ignition on a chainsaw
Often, chainsaw manufacturers equip their units with starters that work on almost the same principle, namely: in the groove of the saw housing is a handle, through which a cord is passed. When the handle is suddenly lifted, the cord is pulled through, which engages the drum of the ratchet mechanism. This is how the cylinder with the studs, which is located on the shaft, is driven. At this time, the crankshaft makes several revolutions, leading to compression of the fuel mixture, which at this moment is between the cylinder head and the piston. When you lower the handle, on the contrary, the ratchet and the studs lose their contact, which causes the shaft to stop.
chainsaw starter design and principle of operation
Increasing the power of the chainsaw increases the amount of fuel mixture, which must be ignited when starting the chainsaw. In this case, to start the engine, you need to increase the number of jerks of the starter cord. To accelerate the return of the drum mechanism manufacturers use a special steel starter return spring, which has excellent elasticity.
Chainsaw starter cord spring
In the case of a breakage of the spring it is necessary: to remove the cage mechanism, pull out the spring, fixing the upper part of it with the finger and pulling aside a little the starter handle. Then, wind the new part, avoiding kinking and twisting the new spring element, then carefully fix the cage.
Adjusting the ignition: where to start?
If all of a sudden the chainsaw does not start and this is not the only such case, then the adjustment of the ignition of the chainsaw will be more important than ever. It should be done in this sequence:
- Examine the candle for malfunctions. Valid candles are always dry.
- Finding that the candle is wet enough, you should shift your attention to the carburetor, the malfunction of which can lead to the flooding of the spark plug part and prevent sparking. The presence of a darkish plaque is a signal that there are problems in the cylinder-piston elements of the motor.
- If the previous point of inspection did not give visible results, the next step is to check whether there is a spark. To do this, you need to move the cable coming from the spark plug to the cylinder. When the gap between the two parts is too small, a spark is sure to be produced.
- If no spark is detected, the next step is to check the voltage. Its absence can only mean one thing. the integrity of the wire is broken.
- If the high-voltage cable is good, it’s worth rechecking the ignition angle, because failure to do so can cause the spark to either “rush”, appearing too early, or “lag”, not having time to ignite the fuel. After all, all leading experts make the Accent on the fact that the adjusted gap between the flywheel and ignition coil. the basis for timely formation of spark, and as a result. trouble-free engine start and smooth operation.
- Another option to consider after checking and correcting all the previous points is the spark plug itself, which might be worn out and need to be replaced with a new one. A benign spark from a new working spark plug looks like lightning. If it is dull, it is worth examining the quality of the spark in detail.
To do this, connect the high-voltage wire directly to the spark plug. Then with jerky movements the starter is started. Based on the results of the observations, you can conclude whether or not you need to change the spark plug.
If the machine fails to start, the first thing to check is the spark plug, which ignites the fuel in the cylinder. Start by removing the high-voltage wire to which the spark plug is connected. Then unscrew the spark plug itself from the cylinder head and inspect its condition. The spark plug when working properly should be dry and small deposits on the ceramics of a light color:
- If the spark plug is wet, there is a problem with the carburetor. It is necessary to adjust and set the fuel level in it;
- The soot on the walls of the candle is dark or black, it means a malfunction in the piston group.
If you find no apparent cause of the fault here, the spark plug is dry, the fouling is light continue to go from the reverse. As this is the final point of ignition of the mixture. Grasshopper crankshaft cause a breakdown. Now check to see if the spark is coming from the spark plug. It’s the ignition unit.
Check whether there is a spark is not a problem, just take the high-voltage cable to which the plug is connected, bring it to the cylinder block, exposing them not a big gap, so that you can notice the jumping of the spark between them. Then pull the starter cord and see if there is a spark and what color it is. A working spark plug should give a lightning-like spark. How it looks like, look at the picture offered for your attention, you can see everything on it.
If you don’t see any spark, check with a test light, if you don’t have a probe, check the high-voltage cable. Probably a break in the place where it is most often kinked. If the wire is fine it is possible that the problem is the wrong ignition angle. It can be too early or too late, in both cases the chainsaw will start well and will not work.
Now let’s try to set the correct gap between the moving and fixed contact. Ideally it should be 0,2 mm. You can check it with a feeler gauge, luckily it’s not in short supply.
That was a description of the faults of the older generation of chainsaws. The new generation includes modern Goodluck, STIHL and Husqvarna chainsaws.
Modern systems are equipped with chips that regulate all of the above faults. Independently set ignition timing depending on engine rpm and power to the cutting assembly. Significantly saves fuel without detriment to power. Also much easier to start the saw, regardless of weather conditions.
In addition to what I have read here is a video for getting the full picture.
How to Advance the Ignition Timing on your Chainsaw
2 Комментарии и мнения владельцев on How to Adjust the Ignition on a Chainsaw
I bought a STIHL chain saw but I’ve hardly ever used it. only repair. Grass trimmer gasoline Yermak cause of trouble. I can not start.
Ignition advance angle
The mechanical device and the factory setting of the magneto ensures that the ignition timing coincides with the optimum position of the moving piston. For four-stroke gasoline engines, the spark must strike before the piston reaches the top dead center. this is because the process of complete combustion of the air-fuel mixture takes a certain amount of time. The speed of movement of engine parts is comparable to the speed of ignition of fuel, so the piston has time to travel a certain distance from the moment the spark flashes until the burning gases create an extremely high pressure.
There is an ignition advance angle for each engine. It is equal to the crank rotation, expressed in degrees, from the moment of penetration in the interelectrode space of the spark plug to the moment when the piston is at the top dead center. This value depends on many parameters, including the engine design and the properties of the fuel mixture.
In practice, when an engine is mass-produced in a factory, the ignition timing of each item is not adjusted individually, but the corresponding marks are placed on the rotating parts, which must be aligned during assembly.
When ignition tuning is required? There are basic symptoms of a malfunctioning system:
How to check ignition timing chainsaw
If this is the case, there is no need to rush to the service center. Try adjusting the ignition yourself first.
STIHL 180 clearance between the coil and the magnet
The STIHL MS 180 chain saw is one of the most reliable models in its class. But technology is technology, and sometimes malfunctions occur that may require you to repair the STIHL ms 180.
Read more about repairing assemblies in this article.
Is it possible to repair the saw with your own hands?
This is the first question you ask when you own a STIHL 180 chain saw and for some reason it no longer functions correctly. There is no unequivocal answer to this question. The correct answer is “yes, but do I have to?? of course it is more expensive to have your chain saw repaired in a service center than to try to fix it by your own hands, but by using the services of specialists you receive a guarantee and confidence that your chain saw will be tuned up and adjusted correctly. In general, the choice is yours.
One more small nuance, concerning the choice to repair the saw yourself or not, is that to diagnose the chainsaw and its further disassembly and repair, it is necessary to have some specific tools and certain knowledge of the saw’s design. Otherwise you won’t even be able to unscrew and remove the flywheel without damaging it.
Do-it-yourself saw repairs often break the aluminum fan blades on the flywheel. This happens because they do not use a special crankshaft stop when disassembling, but try to fix it by putting a screwdriver between the saw body and the flywheel blades, which leads to unfortunate consequences. The flywheel nut has a serious tightening torque, and the blades are fragile and unable to withstand such an effort.
Adjusting the ignition of a STIHL 180 chain saw
STIHL chain saw MS 180 is mainly used for cutting wood and other building applications. STIHL 180. STIHL 180 chain saw ignition adjustment. STIHL 180, video. Similar equipment is used very often due to the greater list of functions and abilities. The saw’s main characteristic is that it has reduced vibration, which is essential for the health of the machine. Naturally, during the use of a chainsaw can fail, which means that it must be repaired.
Problems with the carburetor
The carburetor on STIHL chain saws features a single screw that adjusts the idle speed. Always check the idle speed when the machine is in operation. A few simple steps are enough to fix it: Check the air filter and also the spark arrester.
It is worth noting that the repair of the carburetor chain saw STIHL is considered a labor-intensive process. This article takes an in-depth look at adjusting the spark plug for the STIHL 180 chain saw. If for some reason it will not start, proceed as follows:
- Adjusting the carburetor on a STIHL mc 180 Benchmade saw
- Adjusting the carburetor on a STIHL 290 Bench Saw
- Adjusting the carburetor on a STIHL 361 chain saw
- STIHL STIHL 250 chain saw carburetor adjustment
- STIHL STIHL 180 chain saw. Carburetor adjustment
- Adjusting the carburetor of a STIHL 180 chain saw
Ignition on a chainsaw
In order for a gasoline saw to start working steadily at idle speed, the fuel located in the factory cylinder of its power unit must ignite. To do this, any brand-name chainsaw is equipped with a standard ignition system as standard. Its good condition largely determines the ability of the engine to make the first cold start and steadily gain speed when the operator presses the trigger. STIHL chain saw ignition is characterized by its simple design and constant operating principle. By learning their peculiarities, it will be easier for the operator to maintain and repair the assembly himself.
How to set the ignition on the chainsaw?
As with the constant need to adjust the carburetor yourself, a chainsaw used in a private household or on the forest floor should lend itself to timely adjustment of the built-in, regular ignition. The essence of this procedure is to set the gap originally provided between the flywheel of the power unit and the OEM ignition coil. The value of this gap may initially be different. it all depends on the intended use, as well as the design features of the saw. A distance equal to no less than 0.2 and no more than 0.4 mm is considered average. If the gap is not correct, the basic ignition system will not be able to provide the spark required for timely, instantaneous ignition of the fuel mixture.
To initially properly adjust the appropriate gap between the flywheel and the ignition coil on the chainsaw, its owner will need a special plate template. However, buying one for one-time use is not always advantageous. In some cases, the template can be replaced by a homemade one. To make it, the operator will need a plastic smooth bottle, from the side of which you need to cut a thin strip. There should be no embossing on the homemade pattern.
The operator can adjust the ignition on the chainsaw directly in this order:
- First, it is necessary to slightly loosen the plastic bolts designed to fix the element of the regular ignition;
- Next, the magnets provided on the flywheel will need to be brought to the factory coil;
- Then, between the base high-voltage coil and the built-in engine flywheel, a homemade or previously purchased template must be installed. After that, the bolts fixing the coil will need to be screwed in the opposite direction;
- Next, the operator must carefully remove the template.
- At the end, it will be necessary to crank the built-in flywheel. At the same time, you need to make sure that when rotating the element does not touch the coil and other parts of the chainsaw.
If, for some reason, the adjustment of the ignition of the chainsaw led to a permanent contact of the flywheel, then it is necessary to inspect the tendrils that fix it in its normal place. If they are deformed, the fasteners will need to be replaced. source
Does not start or poorly starts the chainsaw.Cause and how to fix.
This part of the gasoline tool has the following typical structure:
- electrical cable;
- spark plug;
- cutoff key.
- magnets placed in the rim;
- ignition coil, consisting of a core and transformer windings;
- spark plug.
The last element is considered one of the most important, because it is by the sight of the spark plug in most cases you can make a visual diagnosis of the entire ignition system of gasoline units.
Spark formation is not an easy process. To begin with, it is necessary to create a magnetic field in the coil itself which is made possible by the 2 magnets. When the contacts of the primary winding are closed, a weak electrical impulse is initiated. Accordingly, when they are open, there is no magnetic field or electromotive force of the secondary winding.
In this case, there is the formation of an electric current with high voltage and fed to the candle, which gives the very spark that ignites the combustible liquid. Usually, at this point, the piston is localized near the dead point, or more precisely, 0.4 cm below its position. It is worth noting that the contact ignition, which was installed on chainsaws back in the early 90s. and which have come down to us together with the used equipment, have already become obsolete in the modern technical stage.
Therefore, in the current modifications, which are presented to us by the leading manufacturers, there is a contactless electronic ignition, which is much easier to adjust and maintain.
This is one of the central issues that concern all chainsaw owners without exception, regardless of their power class and the brand that made it. After all, even if the tool had factory settings, set up strictly according to the rules in accordance with the instruction manual, in the process of work all the same you can not avoid their failures. The reason for this is vibration, intensive loads acting on all systems of the saw and on the ignition as well.
How To Gap An Ignition Coil On ( chainsaws/strimmers/mowers/etc ) quick tip!
- the unit does not start after several consecutive attempts;
- functioning occurs with interruptions, which are noticeable not only at idle speed, but also under load;
- the tool does not produce its full power.
If at least one of these points takes place in the work of the device, it means that it is necessary to reset the ignition on the chainsaw. This means that it simply needs to be readjusted, which you can do with your own hands, without resorting to the help of repair shops and service centers.
The standard ignition system of a carbureted engine consists of:
Ural chainsaw ignition diagram
A magneto is a type of alternator that supplies electricity to the spark plugs. It consists of a fixed coil winding and a permanent magnet attached to the flywheel, which rotates with the crankshaft of the gasoline engine. The moving magnetic field creates an electromotive force in the low-voltage winding, which is converted by the transformer into a voltage with sufficient potential to produce a spark.
In contact magnetos, the first terminal of the high-voltage coil is connected to the spark plug and the second terminal is connected to earth via a mechanical switch. At a certain point, a special design element unwinds the contacts, causing a rapid rise in line voltage and a spark between the electrodes of the spark plug.
To prevent overheating and oxidation of the breaker contacts, a capacitor is connected to the circuit.
The ignition circuit of a chainsaw with a non-contact magneto is based on the operation of the control coil, which plays the role of a voltage regulator. The electronic unit also includes a diode, capacitor and thyristor, passing current with a voltage of a certain value. When it is opened, the capacitor discharges intensely, forming a current in the turns of the primary winding, which is induced into a high-voltage voltage that gives a breakdown on the spark plug installed in the cylinder. The electric network works in pulse mode in the rhythm of the crankshaft rotation and the progressive movement of the cylinders.