How to convert electronic ignition of Ural 4320 chainsaw

Druzhba chainsaw. coil connection

In this video I will show you how to connect the high voltage coil from a 12 volt car to Druzhba chain saw ignition.It happens that a chainsaw Druzhba which has a contact ignition, high voltage ignition coil fails and the spark is lost, while the low voltage coil remains operational.To solve this problem without changing the whole ignition module, we will connect the high-voltage coil from the car, although you can use a coil from a motorcycle or moped at 12 or 6 volts.In order to connect everything, we first need to unwind the upper secondary layer of the coil (high-voltage) from the coil to the beginning of the primary winding.See how to connect everything in the video about Druzhba chainsaw.

One wire from the contacts on the ignition coil, the second wire from the earth to the second terminal of the ignition coil.

Т.e from the primary winding goes to the ignition coil itself, but because the cat.Ignition is powered from 12 volts. Does not go out of order?

condenser must be discarded or cut off

Why don’t you buy a new saw instead of reviving this dinosaur? ?

How many volts does the coil itself in the chain saw?

How to put the bobbin on the spool electron, no ignition on the saw Druzhba Altai 4. 1994г.

According to your scheme put the ignition coil from Izh-5.The spark comes and goes, and then nothing at all. what may be the problem.

According to your scheme, I put the ignition coil from Izh-5.spark comes on and then nothing at all. what may be the problem.

electronic, ignition, ural, chainsaw

I removed the secondary and primary. I wired the coil with 0.8 wire. 150 turns. Need any reel except a transistor. Gas 53,66, ziz130. Also does not fit moto. With electronic ignition. B300 is best.

I’m wondering what that does?this device on druzhba?

this system doesn’t fucking work. I have been suffering for a week, no spark.

such a system does not fucking work. I’ve been struggling for a week with no spark.

Everything works great! It’s just that the coil should be 6 volts. I put from a moped B300. Tried from an old Java (6v). the spark is there but could not start. From a moped works great. Thank you to the author. I did it. You have to check it starting with the contacts.

electronic, ignition, ural, chainsaw

Eh remember the trouble with the ignition before. all the wire from the coil and wind counterclockwise do not remember the diameter of wire and the number of turns. you get the generator and the bobbin on the handlebars.

with non-contact ignition is an option to make such a scheme?

Can you tell me if the contactless ignition is equipped with a conditioner??

Here’s no talking about this and that. it is clear. Can you draw a complete diagram? And to designate the specific equipment, which works 100% with you, it will become clear to someone at once, and for someone else addition.

It turns out I have a friendship from the first years of production. it goes to the ignition the capacitor is inserted separately in the case. how to remake it. not on sale

Nothing complicated there, in principle the primary coil is unnecessary. Plus wire clips on the contact. The coil is connected to the ground and everything works, I connected it this way on my Sid 4.5, it works better than the original.

struggling with the spark of a Chinese there an option to install (magneto) or something else from Minsk?

I used to have a VAZ 21-08 coil on a Vohod motorcycle. But from other machines coil dick start. The question is why all the cars have different coils?

Ural chainsaw ignition with my own hands

On a summer cottage or farm there is always a need for a means of small-scale mechanization. You need a single-axle tractor or cultivator for tillage, and pump for irrigation or firefighting, power plant in case of power outage, which in the countryside happens quite often. And if the dacha or house is in close proximity to a body of water, then there is necessarily a desire to have your own boat or boat for fishing and water tourism with family or friends. But in all such cases a petrol engine is absolutely necessary. It’s unreal to have a separate gasoline engine for each unit. It is tens of thousands, which is not affordable to everyone. Alternative variant. the universal engine, remade from any existing model of domestic production. Its output can be comparable to the output of home-made motor-block engines. 5-6 liters. с. Presence of forced air cooling is obligatory, ignition. from flywheel magneto. After acquaintance with quite a number of single-cylinder engines of home manufacture I have chosen the Ural-2T-Elektron chainsaw engine. Small-sized, lightweight, economical. it meets all the above requirements. Its service life is comparable to that of outboard motors during continuous operation at maximum speed. The engine has a removable gearbox, which also contributes to its versatility, because depending on the magnitude of the load, the presence of a gearbox or direct transmission allows the engine and load to be matched optimally. And one more circumstance. nowadays chainsaw “Ural-2T-Electron” is quite widespread among country-side dwellers. At the same time, the engine has some disadvantages, the elimination of which predetermined the scope of its modernization. The Ural chainsaw engine is factory set for early ignition, and the fixed ignition advance angle is provided by the alignment of the marks on the engine crankcase and magneto and the rigid mounting of the magneto on the crankcase. This is the easiest way to provide the necessary ignition advance angle without the need for any additional parts, assemblies, etc.д. However, the fixed ignition advance has many negative qualities. the need for high revolutions of the crankshaft at startup (600 rpm), a weak spark at startup, increased fuel consumption, the inability to achieve maximum power, backfire, etc.д. As a result, starting the engine will be difficult, the engine at low rpm is unstable. When starting a cold engine, it is necessary to greatly enrich the operating mixture, which inevitably leads to “flooding” of the spark plug, which is incidentally mentioned in the instruction manual of the chainsaw. To avoid injuries, the manual starter is made easily removable. at backfire, the starter rope sharply retracts into the housing and the starter bounces off the crankcase cover. Elimination of the above disadvantages can be achieved by ensuring late ignition when starting the engine and running it at low RPM and early ignition. at medium and high RPM. And, the ignition advance angle must increase in proportion to the engine RPM. OEM carburetor throttle valve control unit becomes unacceptable during modification and requires complete redesign. When preparing the engine for conversion, the saw unit, drive sprocket, stop and handlebar with spring and pivot linkage, gas tank and throttle control lever with cable, as well as the air filter, carburetor, carburetor guard, crankcase cover and deflector are removed from it.

Engine modification is reduced to manufacturing and modification of the following units and parts:

1) crankcase cover to ensure a permanent landing hand starter;

2) carburetor and installing a more technologically advanced throttle control mechanism;

electronic, ignition, ural, chainsaw

3) the ignition system and installation of the automatic ignition advance angle setting system;

6) a subframe for fixing the engine in place.

And now we will tell in detail about these works.


Since as a result of modification the engine start will be carried out at late ignition, it makes sense to fasten the manual starter rigidly to the crankcase cover, which will create the known operational convenience. Remove the central conical grating from the crankcase cover. Use a d2-4 mm drill on the bars of the grille to drill holes in. Then a chisel cuts the bridges between the holes, and a semicircular file to remove the excess metal. On the end plane of the crankcase cover through the centers of the thickenings (where the bridges of the conical lattice were) and the center of the resulting hole, make the marks, and then continue them on the lateral outer surface of the endplate. Departing from the end 4 mm down, using a caliper make horizontal marks. The resulting crosses are tapped and drilled holes d4.1 mm. With the landing ring of the manual starter remove the shoulders and file cut the metal to obtain the same thickness in a circle. On the crankcase cover set the manual starter crank in the right direction. After checking that the holes on the side surface of the crankcase lid end plate is not on the internal stiffening ribs hand starter housing, the latter is attached to the crankcase lid with clamps. Through the already drilled holes of d4,1 mm drill of the same diameter mark the centers of holes on the ring hand starter landing. For this purpose, the drill bit is clamped in the drill chuck, inserted into the hole and with light pressure rotate the drill chuck manually. The starter is released, the formed holes are punched and through holes are made with a drill d4,1 mm. Install the starter in place, aligning the holes on the cover of the crankcase and the starter housing ring. M4x20 screws are inserted into the holes and tightened on the inside with nuts with split spring washers.

Improving the carburetor includes making a new node for adjusting the idle speed and the engine crankshaft RPM control. To do this, remove the carburetor and all four screws fixing the carburetor housing. From an aluminum bar 20 × 20 mm cut a piece of length of 48 mm and make a console mount adjusting the unit according to Fig.1.

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How to adjust the ignition on the chainsaw

At times the ignition of the chainsaw must be adjusted. This action involves setting the correct gap spark plugs between the coil and flywheel. The parameter is depending on the model of the chainsaw. It is specified in the operation manual. The average value is the parameter 0,2-0,4 mm. The correct gap is essential for the spark to appear at the right time, ie. Е. Not before and not much later than the fuel supply.

Adjust the ignition on the chainsaw will help special templates, but it is not always purposeful to get them for one-time use. That’s why you can swap it for 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 set the ignition, acting in the following sequence:

  • Unscrew the ignition bolts to loosen.
  • Bring the magnets that are placed on the flywheel to the ignition coil.
  • To clamp the plastic plate between the flywheel and coil and then screw it back on.
  • Pull out the strip.
  • Spin the flywheel a full turn a couple of times in succession, with all the need to watch that he did not cling anywhere.

If during the diagnostics any malfunctions of the coil were revealed and it was not possible to adjust it, then the part should be replaced, because the repair is unreasonable.

ural 4320 dizel

Design and principle of operation of the ignition system on the Druzhba chainsaw

For over 30 years, until the late 1980’s, Druzhba chain saws were made with contact ignition (mechanical breaker). Its principle of generating electricity is the same as that of more modern electronic systems. The magnetic rotor, mounted on the crankshaft, rotates inside the coils. The primary winding of the coil consists of several coils of thick copper wire and produces a current of low voltage (V, Volts) but rather high strength (A, Ampere).

The secondary winding consists of many turns of thin wire. In a way, this is a step-up transformer. Passing through it, the electrical charge changes its characteristics. And the output voltage is 15-30 000 V with a paltry current (milliampere). Such current is able to give a high-temperature spark (arc) between the electrodes through the gap, which can be observed on each spark plug.

The last modification of this chainsaw with contact ignition. Druzhba 4A was produced until the end of the 1980s. After it was replaced by the Druzhba 4A Electron with non-contact ignition, which is indicated by the prefix in the model name.

Technical specifications

Gasoline saw “Ural-2T-Electron” has the following technical parameters:

  • Engine. two-stroke, single-cylinder, works on gasoline;
  • The vibration velocity on the control handles is 7.9×10-2 meters per second;
  • the power of the unit is 3.68 kW;
  • The weight of the unit is 11.7 kilograms;
  • the fuel mixture consumption is 632 grams per one kilowatt-hour;
  • the dimensions are 46x88x46 centimeters;
  • The working length of the saw mechanism is 46 centimeters;
  • cylinder diameter is 55 millimeters;
  • the fuel mixture consumption at maximum power does not exceed 632 grams per one kilowatt-hour;
  • the volume of the fuel tank is 1.6 liters;
  • motor power after running-in in operation for twenty-five hours is not less than 3.68 kilowatts (five horsepower);
  • the capacity of the lubricant reservoir is 0.24 liters;
  • engine crankshaft rotation speed at maximum power is 6200±200 per minute.

Druzhba saw repair and modernization

Although these saws were discontinued at the turn of the millennium, a huge number of them are in use and sold on the Internet to this day. some are far from exhausting their service life. But even the ones that have lost their looks and got problems in operation. can be easily restored.

After all, the body parts of these saws practically do not wear out, and the rest is subject to replacement. The video will help you avoid complications when disassembling the “Druzhba-4”:

often at repair it is necessary to change bearings of a crankshaft, all oil seals and gaskets.

Not superfluous during disassembly will be and replacement of piston rings. It is also possible to install a repair size piston group.

If your chainsaw is equipped with a gearbox without lubrication, it’s worth installing a more modern one. This will extend the life of the saw chain.

And here is a video of such a gearbox, which shows how it differs from the regular one:

Such new one from “Ural” costs about 3,5 thousand rubles But at the cost of a slightly used “Druzhba” in 4. 5 thousand. this price may seem excessive. The same concerns other elements. So, if you have a functioning contact ignition, then give for a new or install electronic for 500. 600 may not be worth. After all, the main problems with it are caused by damage to the crankshaft oil seal, and if you replace it, everything can go back to normal.

Cost the same as the removable starter, so it’s best not to lose it. Some people fix it firmly on self-tapping screws in its usual place and tolerate some inconveniences in work, and some people fix it on a rope and find a place on the chain saw handle.

It’s cheaper to rebuild the carburettor with a repair kit.

The biggest modifications are most often made with the ignition system, namely: install a car coil instead of the secondary winding of the regular coil. How to do it correctly is shown at

The spark becomes much more powerful, and problems with starting the saw, especially in winter, are eliminated.

The chainsaw clutch almost never fails, but sometimes needs a little repair. It is designed so that at low RPM the L-shaped profile does not open and the reducer does not engage, but if the rivets on which it is attached are loose, it can touch the outer part of the reducer clutch and at low RPM, then the clutch “leads”. It’s worth trying to rivet them harder. And if the cause is not eliminated, in this case, buy a new clutch.

Repair of ignition block of “Ural (Druzhba)” chainsaw

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, d2=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 KD 209;V6. thyristor corresponds to KU 202

Before starting the repair, it is necessary to determine the circuit of the ignition unit. Variant 1. It is necessary to measure the resistance of the generator coil L1 and the secondary winding of transformer T1, the resistance of the control coil L2 and the primary winding of transformer T1, it is not necessary to measure, it is enough to check them for breakage. Then check if the thyristor control circuit is working, by measuring the resistance. Connect one probe to the unsoldered terminal going to the resistor R1, the other to the common ground. In one direction, the resistance should be equal to the sum of the resistances of the resistor and the forward junction of the diode V5 about 2. 4 com. In case of good condition of all windings and thyristor control circuit, you should make a hole of 1.5. 3 mm in diameter in the point of connection of thyristor anode V6 with the capacitor C1 (point А), and after soldering off the coils check diodes V1-V4 and capacitor C1 for good condition. If one of the diodes is defective, it can be soldered by hinged mounting, previously destroying the old defective diode, by drilling. It is better to use a drill for this purpose. If the capacitor C1 is faulty, you must remove it, insert a new one, and solder the lead to the specified point, then fill it back in with epoxy glue. If the thyristor malfunction, I recommend to replace the circuit block completely, removing the old one beforehand, solder with hinged assembly and fill with epoxy glue.

Additionally, if the resistance of the thyristor control circuit is higher than normal, it is possible that the contact between the circuit and the ground is broken, to restore it is necessary: to free the bolt M3 from glue, unscrew it, clean the contact and screw it again, but already a new one (point B), or just solder the hinged conductor, connecting it with the magneto body. If the saw works, at high RPM with interruptions, it is necessary to replace transformer T1. If after a few minutes of operation completely lost the spark. it indicates a failure of thyristor V6, it is necessary to replace the circuit. Second possibility.If the coil windings are intact (resistance of the alternator coil with one lead may be 1 com, this is normal). check if the capacitor lead soldered to T1 terminal is not broken. If all elements of the circuit are serviceable. I recommend that you flip the alternator coil, putting the lead wire. In case of failure of at least one element of circuit, it is better to replace the circuit completely, having soldered it according to the scheme of variant 1, having wound the coil with two leads. If you do not have an alternator coil with two leads, you can install it with one lead, but on the insulation. It is enough to drill out the tubular rivet with a drill Ø5,1 mm and insert a PVC tube Ø 4 mm and at assembly put fiberglass washers and a mounting lobe, for the second lead.

When changing elements good results are obtained with diodes 1N4007 and thyristors KU709B/KU712B. In principle it is possible to put a diode in parallel with a thyristor. this will slightly increase energy and duration of spark. To increase the values of these characteristics even more, the single half-period rectifier can be replaced with a bridge rectifier; the above-mentioned diode is not needed in this case. It is desirable to set the level of thyristor response to 600-700 rpm. it will provide bigger range of ignition advance angle control (now I think they say “torque”) when you change rpm, at the cost of slight worsening of cranking. In any case, after replacing the thyristor or elements in the circuit of its control electrode, ignition timing will almost always be broken, which, in the absence of a stand, will require additional adjustment on the engine.

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On advance angle control. The control pulse generated by the control coil has a bell shape. in the first approximation looks like a sine-wave. So, as flywheel speed is increased, the amplitude of this pulse increases, and at some speed it is enough to trigger the thyristor, i.e.е. reaches the trigger level (I like the term “trigger level”). It is natural, that at this speed the level of thyristor actuation is in the area of pulse top. As you further increase the speed of the flywheel the drive pulse continues to increase in magnitude, while the thyristor trigger level remains constant. This causes the drive signal to reach the triggering level of the thyristor not at the apex but earlier. at the front. Т.е. with the increase of control pulse amplitude, the moment of its equality to the triggering level of thyristor moves from the top on the leading edge to the beginning. The ignition torque changes accordingly. The typical value of this change in flywheel speed from the beginning of spark formation to 5000 rpm is about 15 degrees, with careful adjustment you can get 19. 20 degrees. This is the adjustment that is made automatically. In addition to that there is the well-known setting by rotating the base of the magneto in the seat. is a sort of “zero adjustment”: just compensation for the variation of the magneto elements in order to obtain the specified ignition torque at one point (if I am not mistaken, at 5000 rpm)

Borodach, 1.05.2006. 16:25, wrote:

what does this phrase mean: “It is desirable to bring the thyristor actuation level to 600-700 rpm”. and how do you implement this and what marks can be used to set, in this case, the ignition timing with an ordinary stroboscope?

Regarding the level of thyristor triggering has already been. To reach the desired speed without problems is possible only on the test bench, where the flywheel is rotated by the electric motor. And without it it is a bit complicated: you have to manipulate the level (voltage) of thyristor actuation. Usually MB-1s are set to a minimum of 300. 500 rpm, so it is necessary by including in series in the chain of control coil a resistor to increase this level by 20. 100%, in this case the main thing is. not to choose, t.е. to do in several stages. By stroboscope, IMHO, it makes sense to make initial setting of magneto. And then you need fine tuning at nominal rpm at nominal load. the optimum is sometimes m.б. shifted by up to several degrees.

How much will the ignition timing change from polarity reversal of the coil L1 and do you have a thyristor control circuit for the MB-1, or maybe some better.

Approximately 90 degrees. And threshold of actuation in this case goes away in 2 times. The classic control circuit: the upper lead of L1 is connected to the diode anode, the cathode of which is connected to the resistor divider: the upper resistor (which is on the diode). in MB-1 should be 750 Ohm to 8,2 kOhm, the lower one (which is common). from 51 Ohm (recommended for thyristor used in MB-1) up to 510 Ohm. The output of the divider is connected to the control electrode of the thyristor. The top resistor adjusts the thyristor actuation level. By parameter/simplicity ratio, IMHO, nothing better has been invented yet.

Borodach, 5.05.2006. 18:53, wrote:

I want to redo the ignition, because I don’t like the way it works either!

Don’t run into trouble. Say, a system with a bridge is more sensitive to uneven (unequal) magnetization of the flywheel magnets and asymmetry of magnetic gaps. it shows up as “engine not picking up speed” or “unstable operation. The risk of running into this effect increases with the life of the motor. When using in this scheme, the non-uniformity of voltage, up to which the capacitor is charged, is greater than in the original variant, which leads to increase of load on thyristor in the area of 2000. 4,000 rpm. In principle, instead of magneto MB-1 you can take EM-7. It seems to be a bridge rectifier, but the spark is twice as long. True, the high voltage is slightly lower, so that with a well-sprayed spark plug, the engine may not start. In general, if you take the risk of redoing. It’s better to find a faulty ignition for that, and not to pick a working one.

Urals chainsaw ignition repair. Chainsaw electronic ignition repair. helpful recommendations

After checking the electronic block and testing its coils on the testing device we make a complete disassembly of the electronic block.

The contact terminals of the coils are disconnected from the circuit and the coils are removed from the body of the unit. Cast electrical assembly on the body of the ignition unit is removed completely, that is, the body of the unit must be completely free of all elements. Inspect the coils of the unit for mechanical damage, discoloration of the protective coating. Let’s measure the resistance of each coil against the reference.

Testing-operation-ignition-coilsMechanical damage to the ignition unit coil protective sheath that has not resulted in damage to the protected winding can be sealed with silicone, epoxy resin, parquet varnish, PVA glue. with PF paint and other similar materials.

If the coil itself has been damaged, it should be discarded.

The presence of dark spots or melting on the cover indicates burnout of the coil and its unsuitability for further use.

Testing chainsaw electronic ignition coils.

High-voltage discharge on the electronic blockAssessment of the electrical resistance helps determine with 90% probability whether the coil is working or not.

Charging coil. 3,26kΩ. High voltage coil. 1,4kΩ and 1Ω. Signal coil. 69Ω.

The lower value of resistance by tens of percents says about the inter-twist circuit of the coils, which happens when burning or breakdown of the coil turns overvoltage or overheating of the wire.

Increased value of ohmic resistance or its absence is a complete breakage of the winding in case of its burnout or mechanical damage.

Additionally each coil is checked with a specially made home-made device.

A separate coil is placed in the magnetic gap of the device, the core of which must be between the ends of the horseshoe-shaped core of the device and which forms a closed magnetic circuit: the coil core the core of the device. When the device is turned on, an alternating magnetic field appears between the gaps of its core, and since the core of the coil under test is located in this field, the magnetic field crosses it and the coil winding, thereby inducing an alternating electric current in its conductor.Signal coil-electronic-ignition coil charging coil. 80v-100v. Signal coil. 5.5v-6.5v. High voltage coil: between the high voltage terminal and the terminal on the body voltage will be about 50v-60v; between the terminal on the body and the terminal on the capacitor. 0.4v-0.8v; between the high voltage terminal and the terminal on the capacitor. 47v-52v.

Rewinding coils is not difficult if you have the necessary amount of winding wire and the required cross section, but usually the high voltage coil and charging coil are replaced with a known good. Chainsaw electronic ignition repair.

We used the following elements to assemble our electronic ignition circuit:

VD-KU201 (replaces BT136); D1-EM516; R1-27ohm (KF4-3); C1-0,25-0,5μf (630v). D2-IN4007(LD). When using the thyristor KU-201 element D2 is not needed.

The ignition-charging circuitThe entire assembly is located in the stock body of the unit in place of the old.

Thyristor is shortened in the threaded part (anode). The cathode contact is also slightly shortened.

The whole assembly after adjusting and testing the unit on the device for protection against moisture, dust and vibration is filled with silicone.

This circuit can be assembled by any beginner or someone who is fond of electrical engineering. It contains a minimum of elements and is easy to assemble.

The lucky owners of their own plot of land are sure to have their own set of tools to conduct various household chores. And among them should certainly be an electric saw or a chain saw. But what to choose? After all, it seems that both are perfectly suited for the work being done. But still, it is worth to decide. In fact, they are identical in their purposes, so why pay twice for the same things. You just need to consider the pros and cons of both tools.

So, in terms of mobility and compactness, it is certainly better to fit an electric saw, but, there is immediately one important problem, it is the presence of a socket. Again, you will have to put a lot of effort. The question is whether you are ready to go for it?

The chainsaw also has a number of advantages and, as a consequence, its own merits. Firstly, it is portable, that is, it can come in handy not only on the site itself, but also when you go to the woods or to the neighbors. But, unfortunately, it weighs quite a lot and, as they say, is highly oversized. But it will be indispensable if you decide to go fishing or hunting.

With such a serious choice between two great tools, you should first decide for yourself what you directly want to use these tools for in the future? If you know in advance that you will not use it that often, then of course your helper will be an electric saw. For long-term cooperation will naturally be indispensable a chainsaw.

Another important factor that is taken into account when choosing is the tool’s working life. Keep in mind that the electric saw is designed for short term use, approximately this time varies around 20 minutes. This is because it heats up quickly and further use may be difficult. There are also other factors, for example, weather conditions. If it is raining outside, then again, an electric saw cannot be used, in order to avoid adverse consequences. You always need to keep safety in mind. But in its direct use you can not think about loud noise or excessive vibration. So, it’s virtually impossible to get very tired when you’re working with it.

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And of course, the main indicator for many people is cost. That’s where electric chainsaws have the edge over chainsaws. They cost much less. In addition, if there is a sudden breakdown, the price of spare parts for electric saws is much lower than for its “rival”. But in general the choice is yours.

Malfunctions of a Ural chainsaw and ways to fix them

Repair of chain saw Ural 2T allows you to fix any malfunctions, up to replacement of the crankshaft, piston system, etc.д. Let’s omit major and medium repairs, and consider minor repairs, which are within the power of any untrained user.

Starts and stops: what is the cause?

There could be many reasons. But you always start with the simplest one:

  • Fuel runs out in the tank.
  • Air filter clogged with dust. too rich mixture gets in the combustion chamber, there is not enough oxygen for complete combustion.
  • The breather. a tiny hole in the gas tank lid. is clogged. There is vacuum in the tank and no gasoline is pumped to the carburetor. Clean the breather plug with a fine needle.
  • The fuel filter at the bottom of the tank is clogged. It is pulled out with a hook made of a wire with a fuel hose overlapped on its fitting. But before you do that, it is worth removing the fuel hose from the carburetor. If gasoline is coming out of it in a full stream, then the breather, the hose and the filter are clean.
  • Adjusting the carburetor. The fuel adjustment screw (not the idle speed) is unscrewed by a quarter turn and check the change of combustion engine operation. If it got better, unscrew another quarter turn. If it gets worse, screw it back in. In any case you should remember how much the screw was turned in or out. It is better to adjust with the engine running and warmed up.

Repair and adjustment of carburetor from Ural 2T Electron chainsaw are presented in

Further problems with the fuel supply are of a more serious nature:

Diagnosis of these problems will require disassembly of the carburetor.

For reference: on Ural 2t Electron is a carburetor KMP 100. There is an experience when instead of it put the carburetor from the Chinese moped Viper Activia and even from a motorcycle IZh Planeta. The difference in volumes of fuel in the combustion chamber buy the adjustment of the fuel supply screw. According to reviews, the Ural 2t Electron performs better than the native carburetor. Non native carburetors do not fit on mount pins. They are installed with the adapters from thick gaskets.

KMP 100 carburetor

  • Bad contact with a spark plug in the spark plug socket.
  • When the engine is running, the cap heats up and the contact deteriorates. Cap temperature is felt only when the engine is stopped.
  • In case of other problems with ignition the engine either does not start at all or “shoots” because of a malfunction of adjustment.
  • Cylinder exhaust window or muffler is clogged with soot.

At low rpm, exhaust fumes are small and exit through a narrowed passageway. At higher rpm the passageway is small and the engine is compressed. Remove muffler or entire cylinder head for visual inspection. Soak chain in gasoline or special compound solutions and clean chain if contaminated.

Fouling of the exhaust system, spark plugs, coking of piston rings. the weak point of old chainsaws. 2.5 to 3 times more motor oil (like M8) is put in their fuel mixtures than in modern chainsaws: 15:1 during running-in and 20:1 during regular work. That large amount of oil does not burn out and forms soot.

The saw chain is jammed

Chain links in part or all of the chain may stick because of poor lubrication. Gearbox or clutch may seize due to a tight clog or a broken mechanism. Engine doesn’t have enough power to crank the chain and shuts down. Pull it through by hand, if it does not pull through, check for the cause.

It won’t start, but it has spark

If there is a spark, the ignition system can only be a problem if it is unregulated. The spark on the Ural 2t Electron should ignite when the piston has not reached V.М.Т. 3.66 mm. If the attachment of the ignition unit is loose and it has twisted, the ignition is knocked off. Checked by matching the two factory marks on the block and body. If the spark is there and the ignition is adjusted correctly, then the cause is the above fuel supply problems.

No spark on the Ural chainsaw

The prefix to the name of the Ural 2t chainsaw Electron indicates that this model uses contactless electronic ignition. My previous Ural saw had a mechanical chopper. According to reviews, the electronic ignition unit is one of the weak points of this chainsaw. Its thyristors and transistors are filled with monolithic compound and can not be repaired.

The unit often fails due to overheating and when the engine suddenly stops at high speeds. That’s why it is absolutely forbidden to stop the chainsaw with the stop button or by removing the spark plug cover at high rpm.

The cause of the lack of spark begins to look for the simplest:

Candle wires for chainsaw Ural 2t Electron If the cause is not in them, change the entire electronic ignition unit.

  • Unscrewing the spark plug.
  • The thread or hex key should be shorted to the common ground by pressing on the cylinder with a hand in a dielectric glove or with pliers with an insulated handle.
  • yank the starter and see if there is a spark.

It is important to know that the electronic ignition produces a high-temperature yellow and weakly visible in sunlight spark. The spark from the mechanical chopper is coarse, bright blue and cooler. Therefore, a fine spark on the electronics that is almost invisible in the light is normal. This should not mislead first-time owners of chain saws with a mechanical chopper.

Non-contact ignition of chainsaw Ural 2t Electron

This is what the disassembled ignition looks like without the flywheel

The Ural chainsaw does not pick up revolutions

This problem can occur for many of the above reasons. But there are two particular points that need to be highlighted.

  • If the engine is stable at idle rpm, but crushes when you press the gas, it is a problem with the fuel supply. Fuel is supplied in sufficient quantity to operate at low rpm. However, it is not enough to develop full revolutions.
  • The throttle (gas) cable is torn. The user presses the gas handle, but the throttle in the carburetor remains in the idle position. The cable can break both at the ends, at the attachment points to the handle and the choke, and along the length, inside the jacket.

Why does the spark plug fill up?

Filling of a chainsaw plug (read about the causes and remedies at the link) occurs when a too large portion of the fuel mixture is fed at the start. Less often during operation, when the engine and spark plug are warmed up and the fuel ignites more easily.

A surplus of gasoline can create a conductive medium, inside the hollow diameter of the spark plug, thereby shorting the electrode not on the contacts, but inside it. Excess oil, on the contrary, can create a current insulating environment on the spark plug contacts, so the spark will disappear. In any case, a wet spark plug is not desirable.

There are three reasons this happens most often:

  • The priming pump is pumped up (suction) before starting by pressing the button. Most often it happens when the engine does not start right away, and pump up one or more more more times.
  • The fuel adjustment screw on the carburetor is turned too far out.
  • The diaphragm and levers in the carburetor, which are responsible for the dosage of fuel supply, are out of order.

A wet spark plug is not to be confused with a wet spark plug when the engine fails to start. That is, when there is no spark, and the fuel supply is normal, it is bound to be wet, because the fuel comes in normally, but does not burn out.

Wipe the primed spark plug with a dry rag. With the spark plug unscrewed pull the starter handle several times to blow out the combustion chamber and remove excess fuel. Then check presence of spark and try to start the engine.

If the spark plug pours again, you need to solve the above problems. reduce the fuel supply by adjusting or repairing the carburetor.

Starter repair

The Ural 2t Electron chainsaw has a removable starter. Pulling the cable out of the starter pulls the ratchet and engages the engine ratchet. After starting, the return spring retracts the starter ratchet to its original position.

Cable and spring are interchangeable. The ratchet life can be extended by unscrewing the ratchet from the engine flywheel and placing a washer under it. Then the engine ratchet will come out further, and the meshing will be restored. But the ratchet should not be pulled too far out. There should be no more than 21.6 mm from the engine ratchet tooth ends to the crankcase cover flange end. Otherwise after starting the chainsaw the ratchets will not come out of the grip.

Oil Pump Repair

The oil pump of a chainsaw Ural 2t Electron most often stops working when the oil channels get clogged. They just get cleaned. Also the worm gear may no longer mesh with the pinion. Sometimes the defect can be corrected by turning the screw that locks the pinion. Eventually the position of the parts changes, they become tighter to each other and the meshing is restored. If the teeth are completely worn out, the parts are replaced.

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