Chainsaw Ural 2t electron stalls under load

Chainsaw Ural 3650 – parameters of the chain tool

This model with a modern layout is designed for intensive felling of dry and rotting fruit trees and active sawing of large dry wood.
The branded saw is equipped with a powerful reinforced gasoline engine, pre-equipped with a manual starting mechanism and a highly efficient system of continuous forced air cooling. Options:

• power – 4.96 l. With.;
• branded tire length – 45 cm;
• factory chain pitch – 0.325″;
• weight including cutting parts – 6.57 kg.

The Ural gas-powered tools in this original proprietary equipment are equipped with a high-quality inertial mechanical brake that protects the operator when the cutting set comes into contact with hard objects that cannot be cut.

Ural chainsaw device

Ural gas-powered tools differ from their market analogues created in the post-Soviet countries by improved balancing, thoughtful ergonomics and lightweight design. This simplifies the operation of Ural models, both in easily accessible places and when working in confined spaces.

The Ural brand chainsaws are based on a powerful gasoline 2-stroke high-quality 1-cylinder engine, equipped with a cylinder with fully chrome-plated internal walls, a reinforced forged piston and a large fuel tank with a wide neck. The starter of the Ural branded model is manual. It has easy access for spring replacement and dust removal.

For the continuous connection of the built-in engine and the saw parts, the basic device of the Ural chainsaw includes a high-quality clutch, which is characterized by its unpretentiousness in regular maintenance and high repairability.

The manufacturer has previously included in each Ural model a durable saw set, which includes a metal bar and chain. To lubricate the chain, the power tool is equipped with an unregulated oil pump, which receives lubricant from a separate oil reservoir. The model's tire is equipped with several self-cleaning grooves through which oil is supplied to the chain and distributed along its entire length.

Safety precautions

Important aspects specified in safety regulations cannot be neglected. Here's what is strictly prohibited when working with a gas-powered saw:

• Work without special clothing, safety glasses and gloves;
• Winding the cable around your hand;
• Touching the starting circuit with any foreign objects;
• Transitions made through a moving chain;
• Inaccurate oil filling and spillage of fuel into work areas;
• If the saw needs to be moved over a long distance, then its cutting part should be covered with a special cover. Otherwise, movement will be unsafe.

Protective gloves for working with chainsaws

It is also important to remember that by adhering to safety rules for working with a chainsaw, you can quickly and efficiently trim large trees, saw logs and prepare firewood for the winter

Malfunctions leading to improper operation of the chainsaw

There are a number of malfunctions that must be taken into account when diagnosing, since they can lead to interruptions in the operation of the saw.

1. Wear of crankshaft bearings. If the crankshaft bearings are worn out, runout will inevitably appear on the main shaft where the flywheel is attached. In such a situation, it is impossible to adjust the gap between the flywheel and the ignition coil, which leads to interruptions in spark formation and unstable operation of the chainsaw.
2. Impulse channel is dirty. The pulse channel serves to ensure the operation of the fuel pump; accordingly, its contamination will lead to improper operation of the pump, which will make it impossible for the saw to operate (it will start and immediately stall).
3. CPG wear. As a rule, with increased wear of the CPG, a decrease in compression in the chainsaw engine is observed, which will certainly affect its ability to develop speed.
4. Dirty fuel and air filters.

Possible faults

Chainsaw owners sometimes face the following problems:

1. A poor-quality saw, the chain bites heavily into the wood, produces a lot of fine wood dust, and grinds the wood down like a file. Reason: The chain is already dull; it needs to be sharpened or a new one used.
2. There is a strong knock of the motor, the saw rattles in the hands under load and intensive work. Reason: the carburetor is not properly adjusted.
3. Ural Electron stalls during active sawing or does not start at all. There are several possible reasons: the fuel mixture is of poor quality, the ignition system is faulty, the spark plug needs to be checked for carbon deposits or replaced with a fresh one.

One of the possible malfunctions inherent in the Ural Electron chainsaw is described in the following video:

What to do if the chainsaw does not idle?

Problems with idle speed are considered constant companions of chainsaws. There may be several prerequisites that could lead to stalling at the time of start-up and cranking of the chain when idling, the main ones being:

• air and gasoline filters are clogged;
• poor quality fuel mixture or improper preparation;
• problems with the ignition module;
• a carburetor whose settings no longer correspond to the load on the saw;
• motor elements are deformed or rusted.

A series of actions are performed sequentially:

• wash the fuel hose or replace it with a new one,
• Clean the air filter, which could be clogged with sawdust and dirt particles. Modern air filters are reusable, they can be washed with the addition of detergent, completely removing them from the saw body;
• check gasoline and motor oil, which may be of poor quality or simply not suitable for working with this saw;
• testing spark plugs and carburetor.

Eliminating one or more possible problems will usually restore the saw to its former strength.

Basic malfunctions and ways to eliminate them

The main malfunctions encountered when operating the Druzhba saw:

1. Difficulties starting the engine occur when the level of gasoline in the tank is insufficient or the pipeline is clogged. The defect is observed when the mixture is excessively enriched. To restore performance, it is necessary to blow out the engine by cranking it with a manual starter. If the saw has been stored for several months with a full tank, then the quality of the fuel decreases due to the evaporation of volatile fractions of gasoline.
2. The engine does not start due to incorrect ignition adjustment. It is necessary to set the gaps in the contact group in accordance with the instructions. Additionally, the distances between the spark plug contacts are checked.
3. Insufficient engine power indicates wear of the piston group or the presence of gaps in the connection between the cylinder and the crankcase. The problem occurs when the jets are clogged, which need to be flushed and the carburetor adjusted.
4. Heating of the gearbox housing during operation of the saw indicates a decrease in the lubrication level. To repair a Druzhba chainsaw, you need to introduce a lubricant like Litol-24 or Konstalin-1 into the crankcase of the mechanism.
5. Clogging of the air nozzle and jets leads to interruptions in the supply of the fuel mixture and failures in engine operation. To restore functionality, you need to remove the device and wash the parts in clean gasoline. Check the mobility of the throttle valve - if the element is stuck, the air flow does not reach high speeds and does not ensure fuel intake through the jets.
6. Violation of the cut geometry indicates improper sharpening or deformation of the teeth.

Repair of the ignition system of the Druzhba 4 chainsaw

Childhood chainsaw disease Friendship 4 - difficulty starting a hot engine when stopped in operation. The reason for this is a weak and outdated ignition system. To increase the power of the spark at the plug, it is necessary to repair the ignition. Such a repair will correct the situation even if there is no standard coil.

Step-by-step instruction

1. The high and low voltage windings are removed from the standard ignition coil.
2. Instead of a low-voltage winding, 250 turns are wound onto our coil with special wire (for transformers). You can use PEV2 wire, with a cross section of 0.8-1 mm. We must not forget about interlayer insulation - a new layer of special wires is laid with paper. The beginning of the entire winding is connected by soldering to a standard output to the magnetic core, the other end of the winding is connected with a special mounting wire to the breaker. Then the coil is wrapped with electrical tape or covered with another insulator. The section of the capacitor circuit fed to the coil and the breaker does not undergo changes.
3. Using two wires through a piece of insulating tube, the ends of the connections are made. To prevent short circuits, all the resulting wiring can be placed in one insulating tube.
4. An ignition coil of type B-115 with a removed side resistor is ideal as a transformer. This type of coil is used in ignition of old Soviet Muscovites. It is not recommended to use motorcycle ignitions; they are not powerful enough to provide the required spark. The reel can be fixed to the chainsaw frame using a mounting clamp in any suitable place.
5. The wires from the internal combustion engine are switched according to the following scheme: the first wire, which connects the breaker, capacitor and coil output together, is connected to terminal B-115 with the designation “VK”, the second wire, which comes from ground, connected to the magneto mounting screw, is connected with output B-115 without identification marks. To make the diagram easier to read, it is better to use different colored wires.
6. Finally, the ignition coil is connected to the engine spark plug igniter using a high-voltage wire.

This repair of the ignition system showed an excellent result, the childhood disease of the Druzhba 4 chainsaw disappeared, such a system will work for a very long time.

The only drawback is that the appearance of the chainsaw has changed due to the external coil on the body, and the dimensions have increased. But this is a forced alteration, but the ignition system works reliably and the saw starts at any temperature.

If some points remain unclear, we suggest watching a video on the topic of repairing the ignition of the Druzhba chainsaw.

Ignition of the Ural chainsaw, operating principle of the EM-1 magneto.

The EM-1 magneto ensures that spark formation begins on the spark plug at a chainsaw flywheel speed of 400-600 rpm. Therefore, the magneto is checked for sparking only with the help of an installed starter. The starter rotates the crankshaft of the chainsaw engine. In this case, it is necessary to know and take into account when checking that the chainsaw magneto produces a spark whose temperature is significantly higher than the temperature of the spark generated by the contact magneto.

In this case, the spark is difficult to see in bright sunlight. It is also necessary to know and take into account the fact that the magneto of a chainsaw works normally at a magneto body temperature of up to 85 degrees. If the body temperature exceeds, the magneto may fail. Therefore, when using a chainsaw, It is advisable to take breaks in work to ensure cooling of the magneto.

READ Ignition From a Chainsaw to the Planet

Magneto EM-1 is installed in the chainsaw crankcase on two studs and secured with nuts (see photo-2). If 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 a mark of 6 on the chainsaw crankcase (see photo 2). A spark in the spark plug, that is, between its electrodes appears at the moment when the chainsaw piston does not reach T.M.T. by 3.66 mm.

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

What can be made from a Ural chainsaw?

It is difficult to find someone who has never tried to make useful homemade products with their own hands from a Ural chainsaw. Their diversity is amazing and gives a chance to once again be convinced of the ingenuity of folk craftsmen. Let's consider the main ones:

• sawmill - is made on the basis of a metal frame with a guide along which the chainsaw moves. A homemade sawmill is the simplest homemade product, the creation of which does not require expensive spare parts;
• motor drill - consists of a chainsaw motor and a gearbox that reduces its speed. Useful for lovers of winter fishing, construction and outdoor installation work;
• outboard motor is a homemade device for small-sized boats. It is assembled from a motor, gearbox, shaft, and screw that receives torque from the chainsaw engine. Allows you to reach speeds of up to 16 km/h with relatively low fuel consumption;
• moped from a chainsaw - a bicycle is taken as a basis, which is aggregated by a chainsaw motor. The gear transmission helps transmit speed to the gearbox, which is necessary for easier control of the vehicle;
• tricycle made from a chainsaw "Ural" - a small-sized 3-wheeled vehicle with a welded base. Wheels are attached to the metal body, like on a children's tricycle. The steering and chain drive are what you'll have to tinker with;
• a snowmobile is a unit that is a motorized sled. It has a complex design: in addition to the engine and gas tank, the clutch, transmission, gas switch must be thought out, and the turning of the skis or tracks must be ensured.

There are quite a lot of accessories for the Ural chainsaw. This suggests that the possibilities of using this tool can only be limited by human imagination.

Why does the chainsaw not pick up speed and stalls?

If the chainsaw is unable to gain speed a minute after starting or stalls when the gas trigger is pressed, most likely the carburetor or engine crankcase is leaking. As in the previous case, the problem can be solved by checking for leaks and adjusting the carburetor.

If your chainsaw does not pick up speed and stalls after it has been running normally for about 5 minutes, the cause may be a defective fuel tank breather. The vacuum created in the fuel tank during operation of the tool does not allow the engine to receive the necessary amount of fuel for its normal operation, and for this reason it will be unable to gain speed or stall. In this case, if you stop the tool, open and close the fuel tank cap and start the chainsaw again, the tool will again work normally for about five minutes, after which it will stop picking up speed or stall.

The reason that the chainsaw does not pick up speed may also be excessive carbon deposits in the muffler, which makes it difficult to release exhaust gases, thereby reducing engine power and speed.

If you want to check the tightness of the crankcase, but do not have a special tool, you can use the following testing method.

Algorithm for checking the crankcase for leaks

• Remove the side cover and bar from the chainsaw.
• Unscrew the spark plug and insert a string with knots into the cylinder through the spark plug hole, thereby stopping the movement of the piston and crankshaft.
• You can use an old cord from a starter as a cord with knots, tying knots on it every 3-5 cm.
• Unscrew the chainsaw drive sprocket.
• Remove the oil pump cover and the pump itself.
• Remove the starter from the chainsaw.
• Unscrew and remove the flywheel.
• Remove the carburetor.
• Using a syringe, pour gasoline into the crankcase through the hole under the carburetor in the cylinder, while observing the crankshaft seals. If gasoline flows through them, it means the seals have become unusable and need to be replaced with new ones.
• It is better to entrust the installation of oil seals to professionals.

Replacing the ratchet on a Ural chainsaw

Another reason for a chainsaw malfunction may be severe wear of the ratchet, which is installed on the flywheel bushing of the chainsaw's crankshaft. As a result of such a problem, it is not possible to start the chainsaw engine, since the starter ratchet does not engage the chainsaw ratchet. To do this, disassemble the deflector, remove the crankcase cover, then unscrew the ratchet and replace it with a new one.

Photo-7. Removing the crankcase cover.

Chainsaw gearbox Ural

If, while sawing a chainsaw, the gearbox makes a grinding noise or other extraneous sound, then it is necessary to disassemble and inspect it. It is quite possible that one of the two bevel gears of the gearbox has failed. The gearbox should be disassembled from the side of the saw chain drive sprocket.

Photo-10. Removing the drive sprocket. For more detailed information about the operating rules and methods of disassembling a chainsaw, download the instructions. DOWNLOAD

Photo-11. Dismantling the driven bevel gear.

Photo-12.Replacing the driven bevel gear.

If increased noise occurs when the chainsaw is operating, this may mean that the muffler has been damaged. In such cases, the muffler should be replaced.

Photo-13. Replacing the muffler.

Photo-14. Unscrewing the M5 screw of the muffler.

https://youtube.com/watch?v=jcVhS8q9rqM

Malfunctions of the Ural chainsaw and how to eliminate them

When repairing a Ural 2t chainsaw, it is possible to eliminate any faults, including replacing the crankshaft, piston system, etc. Let's skip major and medium-sized repairs, and consider minor ones, which any untrained user can do.

Starts and stalls: what is the reason

There can be many reasons. But they always start looking from the simplest:

1. The fuel tank is running low.
2. The air filter is clogged with dust. A mixture that is too rich enters the combustion chamber and there is not enough oxygen to burn it out completely.
3. The breather - a tiny hole in the gas tank cap - is clogged. A vacuum is created in the tank, and gasoline is not pumped into the carburetor. The breather is cleaned with a thin needle.
4. The fuel filter at the bottom of the tank is clogged. It is pulled out with a wire hook along with the fuel hose attached to its fitting. But before doing this, you should remove the fuel supply hose from the carburetor. If gasoline flows out of it in a full stream, then the breather, hose and filter are clean.
5. Carburetor misadjustment. The fuel supply adjustment screw (not idle speed) is unscrewed a quarter of a turn and changes in the operation of the internal combustion engine are checked. If it gets better, unscrew it another quarter turn. If it gets worse, they twist it back. In any case, you need to remember how much the screw was unscrewed or tightened. It is better to adjust with the engine running and warm.

Repair and adjustment of the carburetor from the Ural 2T Electron chainsaw are presented in the following video:

Further problems with fuel supply are more serious:

• the carburetor holes, filters, and channels are clogged;
• The carburetor membrane has become unusable.

Diagnosing these problems will require disassembling the carburetor.

For reference: the Ural 2t Electron has a KMP 100 carburetor. There is experience when instead of it they installed a carburetor from the Chinese Viper Activia moped and even from the IZH Planet motorcycle. The difference in the volume of fuel supplied to the combustion chamber is stopped by adjusting the fuel supply screw. According to reviews, the Ural 2t Electron works better than with the original carburetor. Non-original carburetors do not fit the mounting studs. They are installed through adapters made of thick gaskets.

1. Poor contact with the spark plug in the spark plug cap.
2. When the internal combustion engine is running, the cap heats up and contact deteriorates. The temperature of the cap is tested by touch only with the engine turned off.
3. With other problems with ignition, the internal combustion engine either does not start at all, or “fires” due to an adjustment failure.
4. The cylinder exhaust ports or muffler are clogged with carbon deposits.

At low speeds there are few exhaust gases; they only need to exit through a narrowed passage. When the speed increases, the passage is small and the engine chokes. For a visual inspection, remove the muffler or the entire cylinder head. Contaminated parts are soaked in gasoline or special complex solutions and cleaned.

Saw chain jammed

Poor lubrication can cause some or all of the chain links to become stuck. The gearbox or clutch may jam due to heavy blockage or mechanism failure. The internal combustion engine does not have enough power to turn the chain and it stalls. They try to reach it by hand, if it doesn’t reach out, they look for the reason.

Won't start, but there is a spark

If there is a spark, problems in the operation of the ignition system can only be due to misadjustment. Spark in the Urals 2t The electron should flash when the piston has not reached T.M.T. 3.66 mm. If the fastening of the ignition unit is loose and it turns, the ignition is interrupted. It is checked by matching the two factory marks on the block and the body. If there is a spark and the ignition is adjusted correctly, then the reason is the above problems with the fuel supply.

No spark on the Ural chainsaw

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

The unit often fails due to overheating and when the engine suddenly stops at high speeds. Therefore, it is strictly forbidden to turn off the chainsaw with the “Stop” button or by removing the spark plug cap at high speeds.

Setting up and adjusting the chainsaw carburetor

Then (optionally) a more precise adjustment of the carburetor is made.

How to adjust the carburetor of a Ural chainsaw L - jet screw for adjusting low speeds H - jet screw for adjusting high speeds Screw - T at Partner and Husqvarna (at Shtil LA) - adjusting the idle speed of the chainsaw

Setting up the chainsaw is as follows. Screws H and L adjust the ratio of the mixture of gasoline and air, determined by the opening of the carburetor throttle valve. When the screws are unscrewed, the mixture becomes richer, and the speed increases accordingly; when the screws are tightened, the mixture becomes leaner - the speed drops.

The T(LA) screw is designed to adjust the idle speed. The main “tuning” of the chainsaw is done at the manufacturer during the final test. The carburetor is usually adjusted to supply a richer (than optimal) fuel mixture. The factory setting must be maintained for the first hours of operation of the saw. Then (optionally) a more precise adjustment of the carburetor is made.

We begin the adjustment by adjusting the idle speed; to do this, we rotate the T screw (LA) counterclockwise, achieving a complete stop of the chain at stable engine speeds. For further precise adjustment, you will need a tachometer and it is better to entrust it to specialists, especially since in most cases it may not would need.

To adjust the carburetors on the saw, we start with screw L, then use screw H and finally screw T (LA).

Chainsaw carburetor - designation of adjusting screws. We look for the highest idle speed, to do this we slowly turn screw L in different directions. After finding the position of the highest engine speed, turn screw L 1/4 turn counterclockwise. If the chain rotates at idle, the chainsaw should be adjusted as follows: turn screw T counterclockwise until it stops.

Screw H regulates power and speed. Adjusting the carburetor to a lean mixture leads to excessive speed, engine overheating and failure of the piston chainsaw.

Warm up the chainsaw engine at idle speed for at least 10 seconds and turn screw H 1/4 turn counterclockwise. Let the engine run for about 10 seconds, then check the maximum engine speed with a tachometer. If the maximum speed does not correspond to the specifications, the operation should be repeated. When the mixture is supplied too rich, the muffler begins to smoke; when the mixture is too lean, the saw squeals and overheats.

We complete the adjustment by adjusting the idle speed, as already described above. The idle speed is set correctly if the engine runs smoothly at minimum speed and the chain does not rotate.

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Tools, equipment and technology Recommendations for selection. Operation, repair and maintenance. Malfunctions and ways to eliminate them.

Chainsaws

Remaking the ignition of the Druzhba chainsaw

Since the engines on the Druzhba 4A and Druzhba 4A Electron chainsaw models are absolutely identical, the interchangeability of contact and electronic ignition systems on all models is quite possible.

Moreover, it is sometimes possible to remake a failed coil of an old contact ignition and install it instead of a failed electronic version.

Reworking the contact ignition coil

The coil is removed and all the high-voltage secondary winding made of the thinnest wire that has become unusable is removed. The primary winding, consisting of several turns of powerful wire, almost never fails. She is left in place.

Instead of the removed winding, they use an external high-voltage coil (bobbin) from a motorcycle, a two-speed moped of the Soviet period, or a car. The coil is attached in any way in a convenient place. Restore the connection diagram to the same as it was with a stationary winding:

• from the primary winding of the coil to the + (plus) contact on the bobbin;
• from the contact - (minus) on the bobbin to ground (engine housing).

The disadvantage of this option is that an additional part will appear on the body of the Druzhba chainsaw.

The advantage is that high-voltage coils are easy to change and are available.

You can also find descriptions online of how to repair the electronic ignition system of Friendship, which is reasonably considered to be practically unrepairable. This option is also possible, but for this you need to be an experienced specialist in the field of electronics and electrical engineering.

The ignition device on the Druzhba chainsaw is described in the following video, which also provides recommendations for adjustment:

For residents of the USSR, Druzhba was the only chainsaw, always in short supply, but relatively affordable. (Ural was created on the basis of Druzhba as a more powerful option for the timber industry). Hundreds of thousands of Friendships have been issued over decades. Many of them, due to their good maintainability, are still in working order. And spare parts, including two types of ignition systems, can still be found at flea markets and even online at sites like Avito.

Intended mainly for work in logging sites and sawing logs obtained in this way, the Druzhba chainsaw is also indispensable in private households for solving many everyday problems. Not expensive, very easy to operate and repair, successful in technical terms - the Druzhba chainsaw has been conscientiously and effectively serving for more than 50 years, first to citizens of the USSR, and now to Russians. The range of prices for their acquisition is currently wide. In new condition (mothballed), depending on the modification, their cost ranges from 8 thousand rubles. up to 15 thousand rubles, and used ones, depending on the actual condition - from 1 thousand rubles. up to 7 thousand rubles

How to start a Ural chainsaw without a starter

To start the chainsaw, you need to give the flywheel torque. There are several successful ways to do this.

• The ratchet is unscrewed from the flywheel and a bolt is screwed into its place. The pulley is secured to it with nuts. A cord is wound around the pulley, and starting is done by jerking the cord, like the starting engine of a tractor from the times of the USSR.
• The bolt screwed into the flywheel is rotated with a socket head fixed in an electric drill.

The element of this heavy and gas-guzzling saw was industrial logging. In everyday life, it is good for sawing thick trunks into tree stumps. The idea of ​​her as reliable and unpretentious is a myth. Every 50 engine hours it requires deep maintenance, every 100 - even deeper. You can learn about this in detail from the Operating Instructions for the Ural 2T Electron chainsaw (the link leads to a catalog with instructions).

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

But the majority of users of these chainsaws value 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 the nuances of maintenance and repair in this article.

Technical characteristics of the Ural chainsaw

The basis of the chainsaw was a powerful and reliable motor. The Perm plant did a good job creating an excellent model. The declared power was 5 horses or 3.68 kW, the gasoline engine had 1 cylinder and operated in two-stroke mode. Such characteristics made it possible to consider the chainsaw a professional device, suitable even for daily workload.

The imperative task was to make the engine also economical, so the Ural received a low fuel consumption of 632 grams per 1 kW. The cylinder has a diameter of 55 mm and a volume of 94 cm3, a good indicator even for the model of previous years. As a result, the total weight of the device was 11.7 kg, the dimensions are not small, but quite comfortable for long-term use.

With the Ural chainsaw, malfunctions and repairs occur extremely rarely; this is characterized by the high quality of all components and a reliable motor. Ideal for long-term work, because it has a tank with a capacity of 2 liters, the oil tank has been increased to 0.4 liters.

Chainsaws "Ural": malfunctions and repairs

Any tool breaks. And that's a fact. As practice shows, modern foreign chainsaws suffer from breakdowns no less often than domestic gas-powered tools.

Among the typical breakdowns of Ural chainsaws, the most common are faults with motors. They may not turn on, have poor idle speed, stall under load, or not turn off at all.

There may be several explanations for the fact that the Ural chainsaw does not start:

• lack of fuel, its low quality or incorrect proportion of preparation;
• malfunctions with the fuel system: once the gas tank or fuel supply pipes are sealed, which, on top of everything else, also become littered;
• faulty spark plug or flywheel - as a result, there is no spark required to ignite the fuel;
• a dirty air filter through which air, and therefore oxygen, does not pass to start the combustion process;

If the chain saw starts and stalls, the cause should be looked for in the carburetor. It is necessary to adjust its jets so that fuel and oxygen are supplied according to the load that is expected from it.

The situation when the engine heats up and stalls is also familiar to many users of Ural gas powered tools. Replacing the spark plug, oil, cleaning the air filter or replacing the piston can help fix it.

A working motor should run smoothly without jerking.

The ringing knock of the engine when idling Ural chainsaws is a reason to pay attention to the cylinder. It could be damaged and need replacing.

REPAIR OF ENGINE OF CHAINSAW “URAL 2T-ELECTRON”

Quite recently I had to repair the engine of a well-deserved hard worker - the URAL 2T Electron chainsaw.

In this article I want to outline not only the disassembly and assembly operations of a specific engine, but I will try to convey in the most accessible form general methods, techniques and little tricks for repairing two-stroke engines, using photographs as illustrations.

The engine, which was repaired, started only on a very rich mixture for a short period of time and stalled. The compression was good. Adjusting the carburetor and ignition timing had no effect. It was assumed that the malfunction was caused by air leaks before the compression stroke. The gaskets under the carburetor, cylinder and in the crankcase looked intact; the crankshaft seals were suspected.

But what needs to be done before you start disassembling a unit or assembly?

-first you need to clean it from dirt and wash it,

-prepare a workplace and the necessary tools,

- during work, observe caution and the necessary minimum safety rules. Take care of yourself. The saw engine is quite easy to disassemble, the only difficulty is removing the flywheel, for which, according to the instructions, you need to use a device

Instead of this device, I made do with 3 10 kopeck coins, put them under the ratchet, on the end of the crankshaft and, having tightened the ratchet well, hit the coins with a hammer through the hole through a blunt adapter. One hit was enough

The saw engine is quite easy to disassemble; the only difficulty is removing the flywheel, for which, according to the instructions, you need to use a device. Instead of this device, I made do with 3 10 kopeck coins, put them under the ratchet, on the end of the crankshaft and, having tightened the ratchet well, hit the coins with a hammer through the hole through a blunt adapter. One blow was enough.

So, the engine is disassembled.

A little advice. When disassembling, if possible, try to put fasteners (nuts, washers, etc.) in their places (you can see this in the photo), and what doesn’t work, put it in different jars, boxes and put it away from the place of work. So as not to turn it over, mix it up or lose it. By the way, the savings in time and nerves are huge.

My guess about the cause of the malfunction was correct.

The spring on the front crankshaft oil seal has become disconnected.

We clean the cylinder channels and the piston bottom from carbon deposits (we do not touch the side walls and the piston skirt). If replacing the compression rings is not planned, then we leave them in their places, where they have been worn in.

We check the free movement of the rings in the piston grooves and the condition of the crankshaft bearings. After this, you can begin assembly.

We install oil seals and gaskets. Apply the sealant in a thin layer (the principle “you can’t spoil the porridge with oil” is absolutely not suitable here).

After lubricating the edges of the seals with engine oil, install the crankshaft, not forgetting to replace the spring ring.

Let the sealant (according to the instructions) sit in air for 15 minutes and connect and tighten the crankcase halves.

The end of the gasket protruding onto the seating plane of the cylinder is carefully cut off flush with a sharp knife.

We install the cylinder gasket, orienting the cutout of the gasket towards the carburetor to match the hole in the cylinder.

We thread the high voltage wire into the hole in the crankcase and screw it into the hole of the high voltage transformer. We fix it securely so that it does not fall out spontaneously.

Then, pulling the wire back, we install the magneto in place so that the marks on the crankcase and on the magneto coincide.

and firmly secure it with special nuts, with a cut for a screwdriver. We install the flywheel, not forgetting to place adjusting rings under the ratchet; the size from the end of the ratchet teeth to the end of the crankcase cover is 21-22 mm.

The engine of the URAL 2T Electron chainsaw is assembled.

Review of the model range of the first Soviet gasoline saws “Druzhba”

The first Druzhba chain saws were not particularly ergonomic and safe, but they were popular and in demand not only in the Soviet Union. They did not have a chain brake, vibration damping system, or chain lubrication. All they had was heavy weight (more than 13 kg) and high power. These chainsaws were used in logging sites, since their main purpose was and remains felling trees and cutting logs of different thicknesses. So, Soviet MashProm released the following modifications of the Druzhba chain saws:

1. Chainsaw “Friendship 2”.
2. Chainsaw “Friendship 4”.
3. “Friendship 4-A”, chain saw.
4. Modernized saw "Druzhba-4A-Electron".
5. Chainsaw “Friendship 4M Electron”.
6. “Druzhba-5E”, chainsaw.
7. “Druzhba-Altai” chain saw.
8. Petrol-powered saw “Friendship 60”.

Let's take a closer look at each modification of these legendary saws:

Chainsaw “Friendship 2”

This chainsaw has a durable aluminum body and is equipped with a two-stroke single-cylinder internal combustion engine with a power of 2200 W, or 2.99 horsepower. Starting the chainsaw manually, from the starting cable. Massive handles are attached to the fan; vibration dampers, chain lubrication and a braking system are still missing. There was only one way to stop the chainsaw - by cutting off the fuel supply to the engine. The length of the saw bar reached 45 cm. The massive appearance and solid weight of the chainsaw (12.5 kg), as well as shortcomings regarding safety, were an incentive for new developments.

Chainsaw FRIENDSHIP 2

Technical characteristics of the “Friendship 2” chainsaw:

Chainsaw “Friendship 4”

Changes have affected the appearance of the saw; now the handles are attached not to the fan, but to the clamp that combines the gearbox and the engine. The weight of the chainsaw remains the same - 12.5 kg. The power of the two-stroke internal combustion engine has increased to 4 horsepower. The photo shows this model; we see two independent units connected together with a clamp: the motor and the saw unit. The tire is 45 cm long. The model is universal; repairs could be carried out even in the field.

Chainsaw “Friendship 4”

Engine characteristics:

• make and model: MP-1 (single-cylinder, carburetor, two-stroke, air-cooled);
• working volume: 94 cubic meters cm.;
• power: 4 hp (2.94 kW);
• maximum crankshaft speed: 5200 rpm;
• Lubrication system: gasoline with oil;
• connection system with saw set: flange connection fixed with a clamp.

“Friendship 4-A”, chain saw

Changes were made to the design - a lubrication supply system for the saw chain was built in, which extended the life of the headset. The manufacturer strengthened the crankshaft bearing and equipped the Druzhba 4A chainsaw with an emergency brake that is activated when the chain breaks. Two more innovations: a contact magneto and an improved KMP-100 carburetor.

Friendship model 4A

Modernized saw "Druzhba-4A-Electron"

The power of the chainsaw remained unchanged - 4 liters. pp., the modernization affected the ignition system - for the first time, a chain saw was equipped with an electronic ignition. The oil pump, chain brake and carburetor remain unchanged. Saw guide 45 cm.

Malfunctions and repairs of the Ural 2 Electron chainsaw

I purchased a Ural 2 Electron chainsaw. The instruction manual for this tool has been lost. Can anyone describe the procedure for adjusting the idle speed, initial throttle position?

In my tool I adjust the idle speed by changing the length of the throttle cable. Those. For rough adjustment, I unscrew the screw that clamps the cable and pull it out or loosen it with my hands; for fine adjustment there is a stop screw near the gas handle.

I am repairing a Ural 2T Electron chainsaw (1988). I bought a magneto, installed it - it won’t start, it sneezes and jerks my hand like that (it gives it in the direction opposite to the way the starter starts). Well, I think the ignition timing needs to be adjusted. The results are that sometimes he pulls his hand, sometimes later. I have a question. How does it start anyway? Or am I doing something wrong?

There was once a similar case in my practice. Only when the engine gave back - pop and smoke poured out from all sides (from the carburetor, and from under the crankcase too). Although it sometimes started. It turned out that the pin on the piston, which keeps the ring from turning, had weakened, and since it is located opposite the bypass window, it made a groove somewhere around 6-8 mm long in this window. Yes, plus a modified piston, as a result the bypass window opened before the exhaust window. Examine the inside of the cylinder, maybe that's the problem. Insert a sheet of thick paper there (along the height of the cylinder) and trace all the windows with a piece of pencil - you will get a scan of the cylinder, then compare it with the piston. That’s exactly how I defined the problem back then. And look again: isn’t there much play in the piston in the connecting rod? How do the rings feel there (especially the top one)? And measure the compression just in case.

I disassembled the Ural 2 piston chainsaw, examined the cylinder - all the holes have smooth contours, without any grooves. There is not even any output as such, which is very strange, since the saw worked quite a lot. The piston is also normal, the rings are not coked, I compared the rings with the new ones - there are no differences in diameter, the only thing is that the old rings are run-in (smooth). The piston on the crankshaft connecting rod does not play, the pins that lock the rings are also in good condition (do not wobble). The only thing that surprised me was that the pins are directed towards the carburetor of the saw, and not towards the muffler, but after reading the book I realized that this is how it should be, and it is clear that no one removed the piston or turned it over. In other matters, the words were confirmed that he did not climb into the piston. I started looking for the reason in the magneto, I didn’t buy a new one, because I thought that I would probably buy an identical one (they sell it only in one store). I bored out the grooves along which it turns in the crankcase, the result was that at the most extreme position of the magneto in one direction the same thing happened (recoil), and at the other extreme position, every other time there was either a recoil or the effect of being ready to start. That is, probably still due to the fact that it does not pass the dead center. I looked to see if it was possible to bore the groove, but it turned out that it was impossible - there was no place for attaching the coils. I don’t know what to do now, just turn it a little more, but how, you can’t rearrange the pins, they are screwed into the crankcase on such “islands”. It can resharpen the keyway on the flywheel, but for this you need at least a broaching machine; a file will probably turn out clumsily. Or look for a 100% working magneto.

Refinement of the Ural chainsaw carburetor: eliminating factory defects

Since the KMP-100 carburetor was the only one produced in the USSR, several million of them were produced.
With such a massive and long-term production, the product could not be raw and unfinished. All the shortcomings were taken into account and improved at the beginning of production, and the KMP-100 and KMP-100U had no factory, design or technological shortcomings. The KMP-100U carburetor requires modification when the engine from the Ural 2t Electron chainsaw is used for another purpose. For example, like a boat motor.

In this case, it is not the carburetor itself that needs to be altered, but the idle speed control system located on the gas handle.

Finalization of Friendship 4

Many Western chainsaw manufacturers produce tuning kits for their saws to increase power, and service centers have a separate price list with a list of possible modifications. Mainly found in petrol tool service centers in the USA and Germany.

It is also possible to modernize and replace components in order to improve the characteristics of saws from the Druzhba family.

Examples of what can be done:

• Install turbocharging to increase the rate of supply of the fuel mixture;
• Install a more modern carburetor;
• Increase the compression of the fuel mixture;
• Install an electric starter;
• Bore the internal combustion engine and install an enlarged piston;
• Install the decompression valve;
• Leave one piston ring to reduce cylinder running resistance.

The chainsaw starts and stalls - the reason

If the chainsaw starts and stalls during the first attempts to do the job, then the reason may be problems with the chain brake or its jamming due to lack of lubrication. In this case, measure the oil level. If the amount of lubricant is sufficient, then the reason may lie in the tube that leads it to the lubrication mechanism.

Another reason could be a carburetor failure. If it only needs adjustment, you can do it yourself according to the instructions. If the carburetor needs cleaning or repair, then you cannot do without the help of professionals.

Another possible cause of this malfunction is a low fuel level in the tank. In this case, the chain saw stalls when tilted, since the remainder of the fuel mixture ends up in the part of the tank opposite to the place where the suction tube is located.