Clearance On The Trimmer Between The Spool And The Flywheel
The gap between the ignition coil and the flywheel of the chainsaw
Internal combustion engines are installed not only on cars or motorcycles. They are widely used in various tools, such as a chainsaw or a trimmer. In the event of their malfunction, poor start-up, it is often enough to establish the correct clearance between the flywheel and the ignition coil.
Inoperability of the SZ chainsaw is the most common reason why the engine of the tool does not start. It is recommended in most cases to start troubleshooting from here.
Chainsaw ignition module
Here’s what to do:
- First of all, carefully check the spark plug by carefully throwing off the armored wire from the head and unscrewing the plug from the socket using a special key;
- The second is to check the spark supply with the help of jerking the starter when the armored wire cap is put on the candle;
- Checking the gap is the main topic of our article (more details below).
So, a spark plug malfunction will clearly indicate its phlegm. A wet spark device for igniting the fuel-air mixture indicates that there is an excess of fuel in the system, the carburetor is incorrectly tuned, or there are problems in the SZ.
The candle is checked only after drying. That is, it must be thoroughly cleaned with a napkin, the insides of the internal combustion engine should be dried, the feed should be blocked, and then the starter should be started a couple of times so that excess combustible mixture comes out.
Then the spark device is put in place and everything is checked again.
Black soot on a candle
In general, a spark device can tell a lot about the entire ignition system. If black carbon is observed on the candle, then this indicates violations in the communications of the gasoline mixture supply. Here either the ratio of gasoline and oil has been violated, or the carburetor needs to be readjusted. In some cases, this also happens due to low-quality oil.
A dirty candle is cleaned of black carbon with a needle or some other sharp object. Then the electrode is cleaned with sandpaper (zero) until a metallic sheen appears. The spark device is returned to its place, everything is checked again.
The next step: checking the spark supply. The spark device skirt is brought up to the cylinder and the starter is started. If a bluish spark jumps at a distance of 2-3 mm, everything is fine. A spark distance of 0.5-1 mm is already considered a malfunction. There may be no spark at all, and this is also a big problem. Perhaps this is a wire break.
And now we come to the topic of our article. The chainsaw may not start due to a violation of the gap between the ignition and the flywheel magneto. This very gap should be within 0.2 mm. It is very simple to check: a special gasket is placed between the flywheel and the bobbin. If it comes in normally, not too loose and tight, then the gap is normal.
The saw flywheel itself is round, and checking the clearance with a conventional feeler gauge is impossible. It would be more qualified to set the gap according to a special template, but it is not always possible to acquire it. And not everyone can afford to buy a template that is not cheap for a single use.
Clearance between magneto and flywheel
However, instead of a foreign template, you can use a cut-out strip from a plastic container for 1-2 liters from under the juice.
A homemade template is put like this:
- Ignition fixing bolts are loosened;
- A plate is inserted between the flywheel and the bobbin;
- Bolts are tightened.
About the chainsaw and its inoperability
Chainsaw. The installation itself is not that difficult. But having the least initial knowledge is extremely important in order to find and eliminate any defect.
Modern electronics has progressed so much that it has revolutionized the world of instruments. Saws of our days are light and at the same time powerful, equipped with electronic ignition systems ESZ.
Chainsaw ignition system
Not so long ago, saw ignition systems were cam-type. This carried a lot of disadvantages: heaviness, complexity, high cost and much more. And the main drawback of the archaic ignition system is the difficulty of the plant. Some saw model systems could not generate enough spark at all to flash at crankshaft speed.
Modern systems are nearly fail-safe. Saw models are lightweight and durable, the reel is made more professionally and will serve its life almost flawlessly. However, there are also problems, but in most cases they can be corrected on their own.
Consider the main types of chainsaw malfunction associated with the flywheel and the ignition system.
As a rule, the most common ailment of modern chainsaws is the absence of a supply spark. This also directly depends on the shift in the clearance (gap) between the bobbin and the flywheel.
Chainsaw spark problem
Common installation failures are always associated with internal combustion engines. Problems arise in the fuel ignition system, the fuel intake module, in the internal elements of the engine itself.
As for other units of the chainsaw, malfunctions arise there, as a rule, due to failures of the brake mechanism, poor lubrication performance, etc.
If startup difficulties are associated with the engine, then the following symptoms are most often observed:
- The motor does not develop the necessary power;
- Doesn’t start at all;
- It starts up, but quickly stalls;
- Functioning unstable.
As always, experts recommend identifying fault factors in a way of elimination. In other words, you need to go through the chain, diagnosing each node, each link.
How to check the magneto of a chainsaw
Magneto, babin, module is an ignition coil. It may have nothing to do with tool failures at all, and the reason is lurking only in the gap or in another. But in some cases, it is she who becomes a factor in violation.
To check the babin itself, you should also, as in the above case, use by excluding the components from the chain. Or in other words:
- Visually assess the condition of the bobbin case for cracks and other visible defects;
- Check the cleanliness of current communications of various nodes and elements;
- Diagnose the insulation and serviceability of the armored wiring, the reliability of fixing the fasteners, the absence of rust, etc.
- Visually assess the condition of the spark device cap;
- Checking the condition of the candle;
- Diagnostics of the circuit breaker, which is especially important for Chinese-made chainsaws.
Again, as in the case described above, certain points are excluded from this chain, thereby, the cause of the problem is found.
Chainsaw coil check
Babina herself is investigated like this.
- The magneto resistance is measured. However, this option is not always applicable, since you first need to know the resistance parameters. In addition, for the formation of the required HE pulse, it is necessary to separate the indicators of the various semiconductor elements. A sign of a malfunction, as a rule, is the ringing of the circuit through the BB wire and minus. Should show either “open circuit” or high resistance.
- The check can be carried out as follows. use a device that checks for the presence of a spark. It is installed in the open circuit between the BB wire of the bobbin and the candles. The disadvantage of this method is that the device is so very expensive, it is used mostly in serious repair services.
- “Dedovsky” method of verification, which will save on an expensive device. It is used at your own peril and risk when there are no other options. The method of checking is that the cap is thrown off the candle, a carnation is inserted into it. The candle is re-inserted. The stud should be 6-7 mm from the cylinder. The chainsaw starts up. A spark is examined: it should be bright blue, if not, then this is a sign of a malfunction.
The “grandfather’s” method of checking a bobby has many disadvantages. First of all, this applies to electrical assemblies in the system, which can easily deteriorate. The distance between the cylinder and the stud may differ depending on the different models of the tool.
As for tuning the magneto, it boils down to examining the groove on the flywheel. UOZ for most of the current saw models does not need to be adjusted. But it is possible to determine its exposure only by the angle between the mark after the groove on the flywheel and the magnets installed, again, on the flywheel.
Competently and accurately set the gap between the magneto and the flywheel. that’s what is more important.
You should know that the bobbin on chainsaw systems is installed in the fan fuselage near the flywheel. The coil, in contact with the flywheel magnet, produces energy for a spark.
Replacing the coil itself will be much more difficult, since the installation location is too inconvenient. The installation of a new bobbin should be carried out so that the base of the coil is at a distance of 1-1.5 mm above the flywheel magnets.
In some cases, it is recommended to also check the crankshaft bearing for play.
Check the ignition coil on the chainsaw
If the preliminary actions did not help in identifying the cause of the chainsaw malfunctions, then it is necessary to check the saw ignition coil. Diagnostics is performed in several stages:
- Measure the resistance of the coil using a multimeter. To do this, you should know the optimal parameters, which are indicated in the operating instructions. However, due to the use of semiconductor elements in the system, an attempt to “ring” the coil will result in an open circuit reading. This is normal. A positive test result is a sign of a malfunction. T.E.If it was possible to determine the resistance of the coil using a special tool, then it is definitely faulty.
- Check for spark with a special device. This device should be installed in the open circuit located between the spark plug and the high voltage terminal of the saw ignition coil. The readings will be visible on the display. This verification method is more often used in service centers, since the device required for this is expensive and the costs will not be comparable to the benefits rendered.
- Testing the coil with a spark plug, i.e., perform a homemade ignition. To do this, it must be turned out, and then the body must be attached to the cylinder. Now you need to pull the starter and watch the spark. But this method gives only an approximate result, since the flywheel turns faster due to the unnatural position of the candle.
If none of these methods work, or if you need to perform a check in the field, you can proceed as follows:
- Remove the cap from the candle, insert a nail without a cap into the core at a distance of 6-7 mm from the cylinder. This must be done as carefully as possible so as not to damage the part.
- Carry out the steps to be taken when the tool is manufactured. Now you need to look at the presence of a spark and its color. If there is no malfunction, then the spark will be strong and the color will be bright blue.
This method can be used as a last resort and only if there are no electronic components, while it is important to follow the rules:
- It is impossible to completely unscrew the plug, as this can lead to faster rotation of the flywheel, which is not the correct mode of engine operation;
- It should be located at a distance that corresponds to the compression model and the dielectric properties of the fuel mixture, so this parameter can be viewed in the instructions (the value of 6-7 mm is average).
In order for a gasoline saw to start running stably at idle, the fuel located in the factory cylinder of its power unit must ignite. For this, a standard ignition system is provided in the basic configuration of any branded chain tool. The ability of the internal combustion engine to make the first cold start and steadily gain momentum when the operator presses the gas trigger largely depends on its serviceability. The ignition of a commercial saw is distinguished by a simple device and a constant operating principle. Having studied their features, it will be easier for the operator to perform maintenance and self-repair of the unit.
How to check the ignition coil of a chainsaw?
If, after setting the required clearance, the household chainsaw still does not start, then the coil itself is faulty. To determine the exact cause of the breakdown, you will need to do the following:
- Check the part with a device that measures the presence of a spark. for this, the device must be connected to a break in the electrical circuit between the high-voltage factory wire of the standard coil and the candle;
- To make measurements of the resistance of a standard coil. this method is not often used, since the owner of a commercial saw needs to know in advance the exact values of the coil resistance. In addition, in addition to the inductive coil, the ignition contains certain semiconductor elements that help to generate the required high-voltage pulse. Problems in them can only be identified after preheating. To measure the resistance, you will need to disconnect the cap and armored wire from the coil. For an inexperienced user of a chainsaw, this can cause difficulties, therefore, it is best to carry out this kind of check only in specialized workshops;
- Check the coil directly with a candle. for this, you will need to unscrew the standard candle and attach it to the cylinder. Next, you need to sharply pull on the plastic handle of the built-in starter and observe the spark formed between the contacts of the used spark plug. It should be noted that this method gives only an approximate understanding of the health of the factory coil. The fact is that the plug used at the time of testing is not under the required pressure, as a result of which the standard flywheel, due to the lack of the necessary compression, will initially rotate faster.
In addition to all of the above methods, there is one more. the so-called “cardinal” way of checking a part.
To complete it, you need to act in this order:
- First you need to remove the cap installed on the candle and carefully insert a small nail into it. It must be done very carefully so as not to damage the inner cavity of the cap. It is better to pre-bite off the “cap” of the nail used with pliers, since this way it will be easier to remove it from the cap;
- A stuck nail will need to be positioned at a distance of about 6-7 mm from the factory cylinder of the chainsaw engine;
- Next, you need to start the saw motor. In this case, the candle must be screwed into a regular hole in the chainsaw. Starting the engine will activate the garden tool ignition system;
- When starting the engine, you need to observe the spark. When the motor is turned on, it should have a more saturated bright blue color. If the shade of the spark is different, then this indicates a coil malfunction.
Repairing a defective coil is generally useless as it cannot be repaired. A broken part is best replaced immediately.
How to set the ignition on a chainsaw?
As in the case of the constant need for self-adjustment of the carburetor, a chainsaw used in a private economy or on a forest shaft must be amenable to timely adjustment of the built-in standard ignition. The essence of this procedure is to install the gap originally provided between the flywheel of the power unit and the standard ignition coil. The size of this gap may initially be different. it all depends on the purpose, as well as the design features of the saw. The average distance is considered to be not less than 0.2 and not more than 0.4 mm. In the event of a violation of the correct gap, the base ignition system will not be able to generate the spark required for timely instant ignition of the filled fuel mixture in time.
In order to initially correctly adjust the appropriate clearance between the flywheel and the ignition coil on the chainsaw, its owner will need a special plate template. However, buying it for a one-time use is not always profitable. In some cases, the template can be replaced with a homemade one. To make it, the operator will need a plastic smooth bottle, from the side of which a thin strip must be cut. At the same time, there should be no embossing on a homemade template.
The operator can adjust the ignition on the chainsaw directly in the following order:
- First you need to slightly loosen the plastic bolts designed to fix the standard ignition element;
- Further, the magnets provided on the flywheel will need to be brought to the factory coil;
- Then, a homemade or previously purchased template must be installed between the base high-voltage coil and the built-in engine flywheel. After that, the coil fixing bolts will need to be tightened in the opposite direction;
- Next, the operator must carefully remove the template.
- At the end, you will need to scroll the built-in flywheel. At the same time, you need to ensure that when rotating, the element does not touch the coil and other parts of the chainsaw.
If, for some reason, adjusting the ignition of the chainsaw led to constant contact with the flywheel, then it is necessary to inspect the antennae that fix it in its original place. If they are deformed, then the fasteners will need to be replaced.
How to set the ignition on a chainsaw
The ignition of the chainsaw should be adjusted periodically. This action involves setting the correct spark plug gap between the coil and flywheel. The parameter depends on the model of the chainsaw. It is indicated in the instruction manual. The average value is 0.2-0.4 mm. Having the correct gap is important to ensure that the spark appears at the right time, i.e. not earlier and not much later than the fuel supply.
Special templates will help to adjust the ignition on the chainsaw, but it is not always advisable to purchase them for one-time use. Therefore, they can be replaced with a homemade one. To make it, you need to cut a strip from a plastic bottle. The part of the container where there is no embossing is suitable. After that, you can install the ignition, proceeding in the following sequence:
- Unscrew the ignition bolts slightly to loosen.
- Flywheel magnets to ignition coil.
- Clamp the plastic plate between the flywheel and the spool, then screw the bolts back.
- Remove the strip.
- Rotate the flywheel full circle several times in a row, while you need to make sure that it does not cling anywhere.
If during the diagnostics any coil malfunctions were identified and it was not possible to adjust it, then the part must be replaced, since the repair is impractical.
How to determine the advance angle of the built-in ignition?
The design features of the built-in ignition coil ensure coincidence between the factory optimal moving piston position and spark plug discharge. During the operation of 4-stroke power units, the spark must skip even before the piston returns to the uppermost position. This is due to the fact that such engines take longer to burn fuel. In their factory device, the speed of operation of the internal combustion engine parts is equal to the speed of the planned ignition of the refueled fuel. In this regard, the piston manages to pass a certain path from the moment of instantaneous breakthrough of the created spark to the place where the candle is located. Until the period for which the burning gases are guaranteed to have time to create extremely high pressure indicators.
During the mass assembly of engines under normal factory conditions, manufacturers do not perform ignition adjustments. Instead, markings are left on the rotating elements that must be aligned during installation.
Chainsaw ignition adjustment. Basic malfunctions and their elimination
If you cannot start the saw the first time, there may be several reasons. The most common problem is with the spark plug:
- Worn electrode or damaged ceramic insulator;
- Loose fitting of the removable cap (if any);
- Spark walk along the ceramic winding, as evidenced by a brown residue on the outer shell;
- Cracks in the candle cap (a saw with this problem will continue to work, but it may hurt the user when touched).
If no problems were found with the spark plug, it is recommended to inspect the wires coming from the coil. They can be cut off or have other mechanical damage. There may be wire breaks inside the insulation, so sometimes these violations cannot be detected by visual inspection.
The cause of the breakdown may lie in the shutdown switches. It is not difficult to check them. To do this, you must disconnect the wires from the module, and then check the ignition. If a spark appears after shutdown, the switch must be replaced.
How does the ignition of a chainsaw work and how does it work?
The structure of the carburetor engine does not depend on the tool model. Therefore, we can talk about a standard chainsaw ignition system. It consists of the following elements:
- Magneto. It is an alternating current generator. Required to supply the spark plug with electrical current. Outwardly, this part looks like a stationary winding of an inductor and a permanent magnet, which is fixed on the flywheel. The latter rotates simultaneously with the engine crankshaft.
- Spark plug.
- An electrical cable that connects the 2 previous elements.
- Disconnect buttons.
The chainsaw ignition scheme is simple. After starting the tool, a rotating magnetic field is generated by the movement of the flywheel and crankshaft. It creates a moving force in the existing winding, which is transformed into voltage. This potential is enough to create a spark.
Differences in different models of chainsaws can only be whether a contact or non-contact magneto is used. In the first case, one terminal of the winding goes to the candle, and the second goes first to the shutdown button, and then through it to the ground. In the second case, the device has a capacitor, which, when discharged, forms a current.