Ignition of a chainsaw ural electron do it yourself repair

In detail: ignition of a chainsaw Ural Electron DIY repair from a real master for the site my.housecope.com.

The Ural chainsaw ignition is a fairly simple device, but quite reliable in operation. We will talk about how to repair the chainsaw ignition system on our own a little below. The ignition system of the Ural-2T Electron chainsaw consists of a non-contact type EM-1 magneto, an ignition wire, a flywheel, an insulator with a noise suppression device and a spark plug.

Photo-1. Circuit diagram of magneto.

Magneto wiring diagram

In photo-1 you can see the schematic diagram of the magneto chainsaw Ural: - EM-1.

Photo-2 Magneto device EM-1 of the Ural-2T Electron chainsaw.

Appearance of magneto EM-1 of the Ural-2T Electron chainsaw.

The magneto of the chainsaw consists of a generator coil-1, a control coil-2, a high-voltage transformer-3, a base of a magneto-4, VVT-high-voltage output-5, Risks of the setting lead angle-6, an electronic unit-7, a capacitor-8. magneto EM-1 (thyristor, capacitor and resistor, as well as five diodes) are mounted in the chamber of the magneto base and filled with a special sealing compound.

Thus, the magneto works as a whole and in case of failure of one of the installed elements, it cannot be repaired; it is simply thrown away and a new magneto is installed in its place.

We recommend reading articles on this topic on the site https://my.housecope.com/wp-content/uploads/ext/2913 :

Magneto EM-1 provides spark formation on the spark plug at a frequency of rotation of the chainsaw flywheel of 400-600 rpm. Therefore, the magneto is checked for sparking only with the help of the installed starter. With the help of the starter, the crankshaft of the chainsaw engine rotates. In this case, it is necessary to know and take into account when checking, the magneto of the chainsaw generates a spark in which the temperature is much higher than the temperature of the spark produced by the contact magneto.

Video (click to play).

In this case, the spark in bright sunlight is difficult to see. It is also necessary to know and take into account the fact that the magneto of a chainsaw normally works at temperatures up to 85 degrees. it is advisable to take breaks from work, which provide cooling of the magneto.

Magneto EM-1 is installed in the crankcase of the chainsaw on two pins and fastened with nuts (see photo-2). In the event that the magneto fails, it should be replaced with a new one. In this case, the ignition timing is set as follows: against risks-6 on the magneto, they put risk 6 on the crankcase of the chainsaw (see photo-2). A spark in the spark plug, that is, between its electrodes appears at the moment when the piston of the chainsaw does not reach the VMT. by 3.66 mm.

The appearance of a spark corresponds to the angle of rotation of the crankshaft of the chainsaw by 29 degrees to V.M.T., which is actually the ignition timing. Therefore, when carrying out repair or maintenance work, as well as removing the EM-1 magneto, these risks should always be combined.

The chainsaw flywheel is four-pole and is installed on the crankshaft of the chainsaw engine.

Photo-3.Four-pole flywheel of the chainsaw.

The appearance of the four-pole flywheel of the chainsaw.

It is fixed on the crankshaft with a key and fastened with a nut. The ratchet is mounted in the flywheel hub and serves to start the engine. Consider the case of how to remove the flywheel in order to get to the magneto and repair. The flywheel is removed very simply and easily using a ratchet, but I will show you how to do it. a little lower.

Photo-3.1. We block the rotation of the crankshaft.

We block the rotation of the crankshaft.

In order to remove the flywheel, you must first unscrew the ratchet. The ratchet rotates with the crankshaft, so before unscrewing it, you should block the rotation of the crankshaft. We block the rotation of the crankshaft from the side of the drive clutch.

Photo-4. Insert the washer into the ratchet.

Ratchet extraction method

After blocking the crankshaft, our next step is to remove the ratchet. Next, insert an ordinary washer into the ratchet and screw the ratchet back.

Photo-5. We turn the ratchet back with the washer installed.

Using a wrench to tighten the ratchet

To tighten the ratchet, block the rotation of the crankshaft and use a wrench. Simultaneously with tightening the ratchet, the flywheel itself is removed from the crankshaft. The flywheel is removed only in this way, that is, using a ratchet!

Removing the flywheel from the crankshaft

We remove the flywheel and proceed to repair the magneto. As I said a little above, the magneto is not repaired, so it is removed and thrown away. And a new one is installed in its place and the risks are combined.

Hello members of the forum need help I have a saw Ural Electron 2 and how many times the ignition burns out. So I'm thinking of replacing the standard ignition with another one. At the moment I have ignition from a khuzvarna saw.

melkie wrote:
I have a saw Ural Electron 2 and how many times the ignition burns out.

Read the topic: ”> there are a lot of interesting things about the URAL, and about the ignition too.

melkie,
how do you turn off the saw motor? tell me.

BECHA wrote:
melkie,
how do you turn off the saw motor? tell me.

Personally, all my life I have used jamming the closing of the air damper.

Well, I also shut off the shutter with a damper.

Yuri-Electr, of course, thank you for the link, well, I didn't find anything in it on my question.

First, check the BB wire. There are many Chinese wires on sale, the resistance of the terminals of which can be 300-500 MGOhm and higher. Simply put, the contact nut and the wire have no contact at all. Because of this, it breaks through the area with the least resistance - thyristor, coils, etc. In this case, you can change the magneto endlessly. It is better to put the wire straight, i.e. without resistance, candles by the way too. If you haven't thrown away the burnt out magneto, you can try ringing the coils, if you're lucky, collect one working one from several. Conversion to imported goods is not economically feasible and technically difficult. The outer magneto is very sensitive to the clearance, and the clearances in the Urals bearings overlap them at times. Plus, sparking starts at 2000-2500 rpm.

I replaced the BB wire with a copper one, and in the ignition the coils of the electronics itself burn out and the second coil remains intact.

Ignition unit MB-1.

L1 - generator coil, d = 0.063mm, W = 11000 turns, R = 3000 ohm; L2 - control coil, d = 0.1mm, W = 1200 turns, R = 80 ohm; T1 - high-voltage transformer, d1 = 0, 28mm, W1 = 75 turns, R1 = 0.5 ohm, d 2 = 0.063mm, W2 = 6900 turns, R2 = 2000 ohm; E - electronic unit; C1 - capacitor 0.47 μF 630V; R1 - 390 ohm resistor 0 , 25 W; V1 – V5 - diodes, correspond to КД 209; V6 - thyristor corresponds to КУ 202

When replacing elements, good results are obtained with 1N4007 diodes and KU709V / KU712V thyristors. In principle, a diode can be placed in parallel with the thyristor - this will somewhat increase the energy and duration of the spark. To further increase the values of these characteristics, you can replace the half-wave rectifier with a bridge; the aforementioned diode is not needed.
It is desirable to bring the thyristor response level to 600-700 rpm - this will provide a wider range of adjustment of the advance angle (like they say now: the moment) of ignition when the speed changes at the cost of a slight deterioration in the speed. In any case, after replacing the thyristor or elements in the circuit of its control electrode, the UOZ installation will almost always be damaged, which, in the absence of a stand, will require additional tuning on the engine.

Borodach, 1.05.2006 - 16:25, wrote:

what does this phrase mean: "It is desirable to bring the thyristor operation level to 600-700 rpm". and how do you implement this and by what marks can you set, in this case, the ignition moment with an ordinary stroboscope?

Regarding the thyristor trigger level, it has already been. It is possible to bring it to the required speed without any problems only at the stand, where the flywheel is turned by an electric motor. And without it it is somewhat difficult: it is necessary to manipulate the level (voltage) of the thyristor triggering. Usually MB-1 are set to a minimum of 300.500 rpm, so it is necessary to increase this level by 20.100% by connecting a resistor in series in the control coil circuit. to do in several stages.
By the stroboscope, IMHO, it makes sense to do the initial setting of the magneto. And then fine tuning is needed at rated speed at rated load - sometimes the optimum can be. shifted up to several degrees.

Read also: DIY Luaz box repair

The engines of these chainsaws are equipped with an electronic ignition unit. This block is very simple in terms of the scheme, but, like other equipment, it sometimes fails. Replacing it with a new one is not difficult, but it is rarely on sale, especially in rural areas, and it costs a lot. The radio amateur is quite capable of repairing the unit.

The ignition unit of these chainsaws belongs to the class of unified contactless magneto. Structurally, it is made in the form of a briquette of a hardened transparent epoxy compound, which is poured into the assembly, which includes most of the block's parts.

After the repair described below, the unit will become a SCR capacitor. Its scheme is widely known (see figure). High-voltage transformer T1, generator coil L1, coil-ignition sensor L2 and capacitor C1 were used from the previous unit.

When the flywheel with magnets rotates in the coil L1, an alternating current with a voltage of about 400 V is induced. It is rectified by the diodes VD1, VD2. The pulsating voltage charges the capacitor C1.

At a certain point in the period of rotation of the flywheel, a current pulse appears in sensor L2, which, having passed through the diode VD3, opens the SCR VS1. As a result, a discharge pulse of the capacitor C1 current flows through the primary winding of the ignition coil T1, and a high voltage pulse arises in the secondary winding, causing a spark discharge in the spark plug in the engine cylinder.

It is not necessary to dismantle the used parts of the previous block - they remain in their places. You just need to free their leads from the compound. This is not difficult to do, since the compound is transparent and not too hard, but you should work very carefully so as not to damage the leads and their insulation.

Diodes VD1 and VD2 are soldered directly to the freed terminals so that after installing the flywheel in place, it does not touch the parts and conductors. The VS1 trinistor and the zener diode are mounted on a small strip made of fiberglass or getinax and placed in a sturdy box of suitable dimensions. The box is fixed with screws on the body of the chainsaw and connected to the block with three wires in reliable insulation. The wires are passed through three holes with a diameter of 4 mm, which must be drilled in the engine housing near the ignition block.

Experiments have established that KU202N trinistors work stably in winter conditions at temperatures down to -40 ° C. Zener diode D815A can be replaced with D815B or D815V. Diodes - any of the KD105 series or others for forward current and reverse voltage of at least 100 mA and 400 V, respectively.

If it was necessary to replace the capacitor C1, then any paper or film with a capacity of 0.5 will do instead. 1 μF for a voltage of at least 600 V.

Lawn mowers, trimmers, brush cutters. Knowledge base

Malfunctions and repair chainsaw Ural 2 Electron

Got a chainsaw Ural 2 Electron. The management of the operation of this tool has been lost. Can anyone outline the function of adjusting idle, home throttle position?

In my own tool, I adjust the idle speed by changing the length of the throttle cable. Those. coarse adjustment I unscrew the screw holding the cable and pull or loosen it with my hands; for a precise adjustment there is a stubborn screw near the throttle handle.

Repairing chainsaw Ural 2T Electron (1988 onwards).I bought a magneto, put it on - do not start, sneezes and tugs the hand so well (gives it to the side, reverse to the crank with the starter). Well, I think the ignition timing needs to be adjusted. Results - he pulls the hand earlier, then later. I have a question. How does it start? Or am I doing something wrong?

In my practice, there was once a similar case. Only when the engine gave a return - cotton and smoke fell from all sides (both from the carburetor and from under the crankcase too). Although it happened and got started. It turned out that the pin on the piston, which keeps the ring from turning, has loosened, but because it is opposite the bypass window, it has hollowed out a groove in this window with a length of about 6-8 mm in some places. Yes, plus a part-time piston, as a result, the bypass window opened earlier than the exhaust one. Examine the inside of the cylinder, maybe that's the case. Insert a thick sheet of paper there (along the height of the cylinder) and circle all the windows with a piece of pencil - you will get a scan of the cylinder, later compare with the piston. I specifically conditioned this problem then. And take a look: is the piston in the connecting rod not very loose? How do the rings feel there (especially the top one)? And try the compression just in case.

It is not necessary to move the magneto further than the grooves, all the more so to make a new groove in the flywheel. Most likely, the magneto is buggy: either at the factory there is something with the control coil tricky (the wrong side, not the number of turns, the input-output is confused), or the thyristor burned out and opens earlier than the time. In any case, it is better to check the magneto on a working chainsaw and determine whether it is magneto or not. You can also try to turn the wires of the control coil either by itself, or by placing spacers under the magneto, try to move it along the flywheel axis (maybe the control magnets are overlapped there somehow by the power ones) Although these are just my thoughts. And also as an option: try to return the old magneto.

Why is the chainsaw engine Ural Electron does not provide the required power?

Maybe the piston rings are burnt in the piston grooves or the ring is broken. There may also be leaks in the joints of the cylinder to the crankcase, the carburetor to the cylinder, wear and loss of elasticity of the rubber crankcase seals. And another reason - the holes of the carburetor nozzles are clogged.

Is the chain sharpened on the machine, or can it be corrected only by hand?

The Oregon chain for Ural-2T ("Druzhba") has the title 0.404 ″ 64 1.6mm 20 ″ / 50 (Ural, Druzhba) longitudinal and model ORG / 27R64E.

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Faults and repairs of the Ural 2 Electron chainsaw

I got a chainsaw Ural 2 Electron. The instruction manual for this instrument is lost. Can anyone describe the procedure for adjusting idle speed, starting throttle position?

In my instrument, I adjust the idle speed by varying the length of the damper cable. Those. rough tuning. I turn off the screw holding the cable and I pull it out or loosen it with my hands. There is a set screw next to the throttle grip for fine adjustment.

I am repairing a Ural 2T Electron chainsaw (1988). I bought a magneto, put it down. do not start, sneeze and do not cool down, so pulls his hand (pulls away, opposite of the landing course of the starter). Well, I think the ignition timing should be adjusted. Results. then, before pulling his hand, then. I had a question. How does it all start? Or am I doing something wrong?

In my practice, there was once a similar case. Only when the engine kicked back. cotton and smoke fall from all directions (from the carburetor and from under the crankcase too). Although it happened and began. It turned out. a pin on the piston that holds the ring off, and since it is opposite the bypass window, it continued a groove in that window about 6-8 mm long. Yes, plus a machined piston, which opened the bypass window in front of the exhaust.Examine the inside of the cylinder, perhaps it is. Insert a thick piece of paper (at the height of the cylinder) and draw a piece of pencil over all the windows. get a sweep of the cylinder, then compare with the piston. I just solved this problem. And look: the piston in the connecting rod does not play much? How do the rings (especially the top ones) feel? And measure the compression just in case.

Do not move the magnet beyond the grooves, especially when creating a new flywheel groove. Most likely, a magnetic buggy: either at the factory there is something with a control coil (not the side, not the number of revolutions, the input-output is confused), or the thyristor burned out and opens ahead of time. In any case, it is recommended to check the magnetometer on the working chain saw and determine if it is a magnet or not. You can still try to twist the wires of the control coil or it, or by placing it under the magnetic spacers, try to move it along the axis of the flywheel (perhaps the magnets can overlap in some way with force). Although this is just my thoughts. Still, as an option: try to restore the old magneto.

Why does the motor of the Ural-Electron chainsaw not provide the required power?

The piston rings may have been burnt in the piston grooves or broken rings. Leakage may also occur in the joints of the cylinders with the crankcase, the cylinder carburetor, wear and loss of rubber elasticity of the rubber seals of the crankcase. And one more reason. the holes of the carburetor sprayers are clogged.

Is the chain sharpened on the machine or can it be fixed by hand only?

The Oregon chain for Ural-2T ("Friendship") is called 0.404 "64 1.6 mm 20" / 50 (Ural, Friendship) longitudinal and model ORG / 27R64E.

Chainsaws "Ural" have been known for more than half a century: their production began in 1955 at the Perm plant, which had worked for the country's military-industrial complex for many years. Until now, their popularity has not faded: demand still remains high despite the abundance of new foreign brands. Some do not want to overpay: the purchase of the Ural chainsaw is more budgetary than similar devices from leading European manufacturers. The same applies to their maintenance, repairs, which save the family budget.

But most of the users of these chainsaws appreciate the traditional quality, which has been tested over decades of service by more than one generation of people.

We will get acquainted with the features of the legendary saws of this manufacturer, their structure and functionality, as well as with the nuances of maintenance and repair, in this article.

Chainsaws "Ural" - the successors of another well-known brand "Druzhba", which are considered its improved counterparts. Compared to Druzhba chainsaws, they have:

high power;
gear equipment;
removable container for chain lubrication - crankcase;
improved cylinder and starter;
easily removable cutting part of the saw;
upper handle composition;
Hydraulic wedge has been added to the construct.

While there are many advantages to this technique, it is not without its drawbacks. The main ones are:

a large amount of toxic exhaust;
frequent clogging of the air filter;
high gas mileage;
from here come frequent problems with the engine and gear part

Consider the range of gasoline saws from this manufacturer.

Gasoline hand tools designed specifically for tough working conditions and tasks of increased complexity.

The device of the Ural 2t Electron chainsaw is quite simple. The main working details are:

engine;
starter;
reducer;
switch;
cutting headset;
gas tank.

There is also a steering wheel and an element on which the structure can be supported.

Technical features of the chainsaw "Ural" 2t Electron

2-stroke engine that consumes 632 ml of fuel per hour;
high power - 3.68 kW;
46 cm tire with detachable chain;
heavy weight - 11.7 kg.

A productive model with improved functionality. The inertial chain brake and chain stroke in auto mode simplify the operator's tool maintenance tasks.

propulsion thrust - 3.9 kW;
capacious gas tank - 0.55 l;
volumetric oil sump - 265 ml;
maximum bus length - 0.45 m.

Sufficiently compact and lightweight chain chainsaw. Decent semi-professional unit, adapted for medium loads.

It differs from other modifications:

thrust of 3.8 kW;
large tanks for fuel and chain oil - 0.62 and 0.25 liters;
standard chain pitch - 3/8;
long bus - 35-45 cm;
light weight - 6.89 kg.

Professional-grade petrol power tool. Features improved grip, chain brake and power button lock function.

Users note that this model of the Ural chainsaw breaks down less often than others and requires repair.

Industrial grade chain saw. Forces of 5.1 hp enough for all woodworking.

Gasoline tank - 0.55 l;
Carter - 0.25 L;
Tire - 45 cm;
Weight - 7.8 kg.

It is advisable to begin acquaintance with such a technique with the instruction manual. Covers such issues:

the internal structure of chainsaws;
the nuances of refueling;
running-in and rules for starting the engine;
preparation of the device for sawing;
care and storage;
safety standards.

Let us dwell on some of them that can be encountered in the process of using Ural chainsaws.

Resourceful people have long figured out how to convert their outdated Ural models to 92 gasoline. To do this, you need to lower the octane number of AI-92 or AI-95 gasoline by adding 70 g of diesel fuel to one tank of the fuel mixture. The engine practically does not feel the difference with such an additive and operates normally.The proportion for the gas-oil mixture should be as follows: 50 ml of engine oil (preferably not for mopeds) per 1 liter of gasoline.A serviceable and filled instrument can be started. For this you need:

put the switch in the working position;

pump the fuel mixture into the carburetor;

pull the starter;

warm up the engine and get to work.

If the device is completely new or returned from repair, it must be run in, which we will talk about further.

Let's get down to business - let's talk about one technical paradox, which, in fact, prompted this article to be written.

So, there lived - there was a chainsaw "Ural" (and now it still lives and lives). The appearance of this saw is probably familiar to everyone who at least once got involved with serious (not to mention professional) harvesting of wood, in particular, firewood. In the photo she is shown with the carburetor removed.

We will not talk about her primordial ability to do her job (to cut large wood for a long time in large volumes) - you can find a lot of sites on the Internet where all this is described quite clearly and in detail. For the same reason, we will not talk here either about the advantages and disadvantages of this chainsaw, to talk about whether it is an “obsolete age” or not. For, we repeat, our current goal is not to create a scientific text of a dissertation, diploma or other qualifying work, article.

This chainsaw worked quite well and reliably doing what they want from it, for about 10-12 years. Then interruptions began: it does not start (okay, they replaced the ignition unit, ignition wire, piston, crankshaft oil seals), then it stalls at idle, then the turns are capricious (they replaced the carburetor). The repair was done by a specialist who at one time repaired more than a dozen (if not one hundred) of exactly the same chainsaws - a former forester. As a result, the saw found a new breath and former power. And with a well-sharpened chain (unfortunately, yes, in the Ural, as well as on other chainsaws, the chain also has to be sharpened periodically, otherwise it will be bad to saw large-diameter logs) effortlessly coped, for example, with an oak with a diameter of 50 cm, and with Longitudinal sawing; with not dried out lower parts of poplars with a diameter of 1 m, consisting mostly of knots, constantly striving to clamp the chain (whoever sawed THIS, he will understand what the conversation is about), not to mention the different birches, pines and other maples there.

However, it took a little time - and again malfunctions. This time there was not enough power (lean mixture) and the saw began to stop in the cut. Well, well, they enriched the mixture a little, then another ... as a result, when sawing, it began to emit as much gas as, probably, an army all-terrain vehicle does. What was especially well observed in calm sunny weather: after work for 5-10 minutes, the entire surrounding space was filled with such thick, heavy, bluish smoke, which there was no way at all to dispel, so it was necessary to urgently evacuate from there about 20-30 meters. the simple reason that there were signs of suffocation (and at the same time, again, it stalled in the cut under increased load). Well, from a distance it seemed to people that a smoke bomb was periodically triggered.

On the one hand, the fuel-air mixture is very rich. On the other hand, little fuel enters the cylinder, i.e. mixture ... poor. Purely by chance, it was discovered that when a small pressure was applied to the gas tank (by mouth - for lack of a more suitable pump at that moment), the engine speed stabilized, and for some time the saw worked acceptable. Until the next interruptions and stops.

So what is it? They removed the carburetor and disassembled it. No malfunctions were found at all. The hole through which the vacuum is supplied from the engine crankcase (shown in the photo with a yellow arrow), which ensures the operation of the fuel pump, was not clogged.

Just in case, we cleaned the carburetor channels, as well as this hole with a special compound (by the way, it is called “Carburetor cleaner”, sold in car dealerships). They assembled the saw ... and it worked as if nothing had happened. True, for a relatively short time. After a short time, the same symptoms recurred.

The carburetor was removed again, and then the cylinder head. Of course, this is not a car, so the gasket (between the cylinder head and the crankcase) is quite simple there (well, not cardboard or rubber, of course). And this is what it turned out (it can be clearly seen in the photo).

Apparently, the specialist who made the repair, whether by mistake, or for some other reason, oddly enough, incorrectly installed this very gasket. It's practically symmetrical. “Practically,” because there is a small cutout in one place on the inside. So, this cutout should be opposite the hole in the cylinder head - the very one through which the chainsaw crankcase communicates with the carburetor pumping chamber; through this hole, pressure from the crankcase enters the carburetor, thereby ensuring the operation of its boost pump. In this same chainsaw, this hole was blocked by a cylinder head gasket, and the cutout in it was located in a completely different place - where it is not needed at all (this is shown in the photo).