4 main malfunctions of the Druzhba 4 chainsaw and their repair - from carburetor adjustment and ignition settings to modification

Possible problems

The main problem that arises during repairs is the lack of necessary information on repairs.
This is explained by the fact that many foreign manufacturers believe that the saw should be disposed of after a certain period of use. Therefore, many craftsmen have certain doubts, especially when repairing budget models. But expensive professional models also create certain difficulties:

1. The first problem is supplying expensive spare parts.
2. For maintenance and repair of some components, special equipment is useful.

Of course, it is possible to replace original spare parts with Chinese analogues, but judging by the reviews, this method is of little justification. Such components produce only half the resource.

Characteristics

Over the 60 years of production, the design of the Druzhba chainsaw and its characteristics have changed insignificantly.

The general parameters are:

• weight when fully equipped - 12.5 kg;
• dimensions - 865x460x500 mm;
• saw bar length - 450 mm;
• The fuel tank capacity is designed for 1.5 liters of fuel liquid;
• spark plug - any with a diameter of 17 mm.

The main difference between the modifications is power. It is indicated by the number in horsepower at the end of the model names.

Friendship 2

The technical characteristics of this model are as follows:

• engine power - 2.2 kW;
• saw starting type - manual;
• lack of a rotary gearbox.

What makes Druzhba 2 different from the first model is the presence of a device for braking the chain, which made it safer: the tool cannot accidentally injure the worker or the people around him. The material from which the case is made is reliable and can withstand any temperature changes.

Friendship 4

This model received a gold medal at the World Technology Exhibition in Brussels in 1958.

The technical characteristics of the chainsaw are as follows:

• power - 2.94 kW;
• engine oil tank volume - 150 ml;
• total shaft rotation speed - 5000-5400 rpm;

A gas-powered saw can cut through a trunk with a diameter of up to 50 cm in 1 minute.

Friendship 4M electron

The Druzhba 4M electron chainsaw is distinguished by the fact that this model is equipped with an electronic non-contact ignition system, which significantly increases the reliability of the engine.

The technical characteristics of 4M are as follows:

• power - 3 kW;
• fuel consumption - 720 g/kW h;
• the distance between the spark plug electrodes is within 0.6-0.7 mm.

The inner walls of the aluminum cylinder liner are plated with chrome to increase wear resistance. The model is equipped with rubber shock absorbers that reduce the transmission of engine vibration to the handles. The Druzhba-4M model uses a KMP-100U carburetor, and with the Druzhba 4A modification, the use of forced chain lubrication began due to the installation of an oil pump. This made it possible to significantly increase the service life of the chain and guide bar.

Model range overview

All Druzhba chainsaws produced were equipped with an air-cooled MP-1 engine; the air was supplied by a flywheel on which the blades were made. For power supply, a carburetor with a diaphragm was used, which ensured the supply of the mixture regardless of the position of the tool. The high power and weight of the equipment limited the scope of use of the tools that were supplied to logging enterprises. To operate the power unit, a mixture of gasoline and oil for two-stroke engines was used (which was replaced by the M8 engine).

Friendship 2

An early example of a saw, equipped with a 3 hp motor. The handles, made of steel pipe, are bolted to the engine flywheel housing. The design does not provide damping pads at the motor mounting points or a chain brake. The tool is lubricated manually; a centralized fluid supply is not installed. The production of the tool continued for several years, after which chainsaws with an improved design came to replace it.

Friendship 4

The handle is secured to a separate cast clamp placed on the engine crankcase. The MP-1 engine capacity remained the same (94 cm³), but modifications to the gas distribution diagram and installation of a modernized carburetor increased the power to 4 hp. The permissible number of revolutions has also increased (up to 5200 per minute), while the weight of the tool has remained unchanged (12.5 kg). The chain lubrication system was not installed at the factory; the owners subsequently modified the tool themselves.

Friendship 4-A

The shortcomings identified during the industrial operation of early models of Druzhba saws led to the creation of another modification, 4-A. A system for supplying oil to the blade (by gravity) was introduced into the design, and reinforced bearing supports for the crankshaft began to be used. The chainsaw now has an emergency brake that is activated when the chain breaks. The engine was equipped with an improved KMP-100 carburetor and a modernized magneto. The power and other technical characteristics of the saw remained unchanged.

Friendship-4A-Electron

To improve performance characteristics, a transistor ignition unit was installed on the saw, which ensured stable sparking. The engine began to start at low air temperatures without preheating. The rest of the instrument has not undergone any changes.

Friendship 4M Electron

The Druzhba M modification received an automatic lubrication unit for the working chain. The damping elements were modified, and rubber linings with increased wall thickness began to be used on the handles. To prepare the working mixture, a KMP-100U membrane carburetor is used; fuel fluid is supplied by gravity. gbks weight is 12.5 kg; For felling trees, a 450 mm long tire is used.

Friendship-5E

The chainsaw is distinguished by the use of an engine with increased power to 5 horsepower. The design uses a conical main pair, which makes it possible to transmit increased torque and at the same time reduces the weight of the equipment to 11.7 kg. The attachment points of the power unit to the frame are equipped with rubber bushings, which reduce the level of vibration during operation. An automatic chain lubrication system has been introduced using a pump that supplies fluid from a separate tank.

Druzhba-Altai

The saw is a 4M unit assembled at the production site (Altai). The equipment was equipped with a modernized KMP-100U carburetor and a contactless ignition system. A pump is used to supply fuel. The equipment has no external differences, except for the use of a protective casing for the air filter. The chainsaw has improved starting characteristics. Production of products ceased in the second half of the 90s.

Friendship 60

The saw is equipped with a two-stroke single-cylinder engine with a power of 3 hp. with a working volume of 94 cm³. A cable starter with forced return of the cord to the reel is used, the speed control is located on the right handle. A gearbox with a gear ratio of 0.319 is used to drive the chain. Torque from the crankshaft is transmitted to the gears by an automatic centrifugal clutch, which requires adjustment during operation.

How to adjust the carburetor on a Druzhba-4 chainsaw

Adjusting the carburetor of the Druzhba-4 chainsaw is required when the engine starts to work incorrectly - it stalls at idle, does not pick up speed when gas is applied, and “fails.”

To access the adjusting screws of the KMP-100 carburetor, you do not need to remove the housing cover; they are always open and accessible. There are no screw markings on the carburetor body, like on modern chainsaws. The first screw, which is located closer to the cylinder, regulates the fuel supply at low and medium speeds. The second screw is the main screw, it regulates the fuel supply at maximum speed

Required Tools

A screwdriver (minus) is required for operation. If desired, you can use an electronic tachometer. It will show the number of revolutions before and after adjustment.

General adjustment algorithm

The carburetor is adjusted in different ways. The simplest and most effective is ongoing adjustment during operation.

Lots of gasoline - spin

• The engine is warmed up for 5-10 minutes.
• If in the “full throttle” mode the engine operates as if idling (does not develop speed due to excess gasoline in the fuel-air mixture), the second (farthest from the cylinder) screw is tightened clockwise 1/4 turn.
• If the engine begins to work better, tighten it another 1/4 turn. If the engine starts to stall when the gas is fully applied, the screw is unscrewed back.

Low on gasoline - unscrew

If the engine stalls in the “full throttle” mode (there is not enough gasoline in the fuel-air mixture), the adjustment begins by unscrewing the second screw by 1/4 turn and testing the operation of the engine. If it gets better, unscrew it some more until the engine begins to “choke” and run as if idling at full throttle. Then the screw is tightened back.

After adjusting the second screw, check how the engine operates in the transition from idle to medium and maximum speed. If there are dips, unscrew the first screw 1/4 turn and test changes in engine operation.

As a result, the optimal operating mode of the engine is found through such trial regulation.

Adjusting the idle speed on the Druzhba-4 chainsaw is done using a screw located on the gas handle. Its position determines how far the throttle valve in the carburetor is open at idle.

Idle speed is adjusted based on two requirements:

1. The engine should not stall.
2. The chain should not spin.

Adjustment in a different sequence is possible. The screws are first tightened to the end, then unscrewed by 0.5 - 3 turns (different sources indicate different numbers of turns).

The video shows a simple and understandable process for adjusting the KMP-100 carburetor on the Druzhba-4 chainsaw from the screws position “tightened completely and then turned out”:

For beginners, we recommend watching a more detailed video about adjusting the KMP-100U carburetor of the Druzhba-4 chainsaw. The author of the video tells everything that is useful and everything you need to know. Just a whole step-by-step guide from A to Z.

Step-by-step algorithm

1. Unscrew the fastening screw.
2. Remove the fuel hose.
3. Unscrew the top damper cover.
4. We remove the carburetor.
5. Remove the membrane cover to adjust the level. You need to unscrew 6 screws in a circle.
6. Let's half the body and assess the condition of the membrane, it must be intact - this is the main thing, cracks, scuffs, and tears are not allowed.
7. We evaluate the performance of the mechanism responsible for the operation of the valve.
8. We blow through all the holes and clear out any debris if there is any.
9. We set the level by adjusting the height of the tongue; it should be on the same edge as the body.
10. If everything is done correctly, then by applying, for example, a ruler, you will see that the tongue and the edges of the body are on the same level.
11. We unscrew the screw with the needle from the central jet and assess its condition, clean everything from dirt, if there is any, blow it out in any case. The screw located above, also visible in the photo, is responsible for idle speed; it also needs to be unscrewed, the condition assessed and blown out with air.
12. This completes the cleaning, put everything back together in the reverse order and put the carburetor back on the chainsaw.
13. Don't forget to replace the air filter and pump up the fuel before starting.
14. Let's try to start the chainsaw.

Possible nuances and problems

In any case, when tightening the screws all the way, you need to remember the number of turns made for each screw. This will make it possible to return to the original adjustment if suddenly the chainsaw, adjusted according to the recommendations, does not start at all.

Electronic ignition unit for chainsaw

Despite the widespread use of imported chainsaws, the population, especially in rural areas, still uses many domestic “Druzhba” and “Ural” machines. Both saws have a common drawback that I also had to deal with - the fragility of the electronic ignition unit. This problem is not new - see the article by P. Ivanov “Repairing the ignition unit of a chainsaw” in “Radio”, 2003, No. 2, p. 45. Nowadays it is not difficult to buy a block, but it is expensive and does not last long. I decided to start developing my own design, which I bring to your attention. Unlike the one mentioned above, the ignition unit does not contain remote elements and fits entirely into the original dimensions of the factory unit. The board of the old unit must be removed. The block diagram is shown in Fig. 1. Generator coil L1, ignition coil (high-voltage transformer) T1, capacitor C1, induction ignition pulse sensor L2 and a duralumin base were used from an old ignition unit. The remaining elements are newly introduced. Rice. 1 Schematic diagram of the device When the flywheel rotates, the generator coil L1 generates an alternating current, which, after rectification by the diode bridge VD1-VD4, charges the capacitor C1. At a certain position of the flywheel, a short pulse of positive polarity appears at the terminals of the sensor coil L2, which, passing through the diode VD5 and the current-limiting resistor R1, opens the thyristor VS1. Capacitor C1 is discharged through an open thyristor and the primary winding of the ignition coil T1. Its secondary winding forms a high voltage pulse, which is then supplied to the spark plug. The amplitude limiter of the opening pulse is assembled on transistor VT1, resistor R2 and zener diode VD6. As long as the voltage on the control electrode of the trinistor VS1 does not exceed the stabilization voltage of the zener diode VD6, the transistor VT1 is closed and does not affect the control electrode circuit. When the zener diode VD6 opens, current begins to flow through it and resistor R2. A voltage appears across resistor R2, which slightly opens transistor VT1, which shunts the control electrode circuit of thyristor VS1. As a result, the pulse amplitude is limited to about 4 V at the zener diode indicated in the diagram. This voltage is enough to reliably open the thyristor. In order for the described design to fit into the dimensions of the factory ignition unit, it is necessary to modify the thyristor. To reduce its length, the threaded shank was shortened (1-2 threads were left), the cathode and control leads were also shortened to a length of 4...5 mm. Before shortening the lead, it must be compressed in two places near the body using side cutters with blunt cutting edges. Then, above these places, the lead is bitten off and the cut is soldered with solder. The terminal can be compressed no closer than 2 mm from the SCR body, otherwise the insulator will crack. This compression is necessary to increase the contact area between the internal conductor coming from the crystal and the external terminal of the SCR. The unit is installed using rigid copper wire with a diameter of 0.4-0.45 mm in vinyl insulation. Diodes VD1 - VD4 are assembled closely into a block and their terminals are soldered in such a way that on one side of the block there are AC terminals, and on the other - DC. The transistor is secured with the screw that was used to secure the factory board. A petal is placed under the transistor, to which the leads connected to the body are soldered. Resistors, diode VD5 and zener diode VD6 are soldered to the terminals of transistor VT1 by surface mounting. Capacitor C1 is placed in the same place, and the bridge VD1-VD4 is placed in the same compartment. The wires from coil L1 to the bridge are flexible, of the same cross-section. The wire going to the anode of the thyristor is soldered to its body. Before filling with the compound, the thyristor is held “suspended” on rigid wires in such a way that it does not protrude beyond the dimensions of the unit, and a gap of about 2 mm remains between the thyristor body and the duralumin base of the generator. After testing for functionality, the assembled unit is filled with epoxy compound, making sure that the parts of all elements close to the edges and the SCR housing are covered with a layer of compound. After the compound hardens, the thyristor is rigidly fixed to the base of the generator. The finished block is shown in Fig. 2. Fig. 2 View of the finished block When installing the block in a chainsaw, it may be necessary to adjust the ignition timing. In practice, it was often necessary to set it earlier relative to the factory mark. If you plan to install the block in a Ural chainsaw, before assembly you need to remove part of the mounting protrusion from the back side of the base, painted in Fig. 3 in blue, flush with the base plane. Under the remaining parts of the protrusion, when installing the block in place, it is advisable to place gaskets made of heat-insulating material, such as asbestos cardboard, with a thickness of no more than 0.5 mm. With a greater thickness, the flywheel may interfere with the block parts. Gaskets are needed because the design of the Ural chainsaw provides for the installation of an electronic ignition unit directly on the wall of the engine crankcase, which becomes very hot during prolonged operation. Rice. 3 Reverse side of the part In the above-described block, instead of those indicated in the diagram, you can use diodes KD105G, KD209 with any letter index, as well as other suitable dimensions with a reverse voltage of at least 400 V and an average forward current of at least 0.3 A. We will replace the KS133A zener diode with KS 139, KS 147, KS 156 with letter indices A, B, G or their imported analogues, provided that the sum of the stabilization voltage of the zener diode VD6 and the voltage of the IBE transistor VT1 does not exceed the permissible voltage at the control terminal of the thyristor. SCR KU202N can be replaced with KU202M, KU205V, KU205G. Tri-nistors in a plastic case should not be used due to their insufficient resistance to overheating. In conclusion, I will add that more than 20 blocks were assembled according to the description provided and they work for a long time and reliably. The unit I assembled and installed on my chainsaw 6 years ago has never failed

Specifications and description

At this point, you can familiarize yourself with each model separately, and determine for yourself which one is most suitable for you. So let's get started.

Power of the saw "Friendship - 2"

This model is equipped with an engine that runs on gasoline and a two-stroke engine. It has a fairly high power, which is about 2.2 kW, due to which the rotational speed reaches 8700 rpm (which is two times less than that of the Ural chainsaw). It is this feature that allows high-level performance to be produced in a fairly short time range.

Moreover, it is a new product that has the highest quality and excellent assembly. The model itself has a fairly presentable appearance, as it is made according to the latest modern developments of the manufacturer. In addition, its owner will be able to enjoy specially designed features that have not previously been used in other models. This advantage contributes to the high balancing of the chainsaw.

Chainsaw friendship 2

If we talk about external developments, then we can say with full confidence that it is very convenient to use, thanks to the handle with an excellent grip built into its design. The functionality of the saw is designed in such a way that you cannot get burned by a running hot engine, which is the case with most other chainsaws from other manufacturers, since it cools itself during operation.

The body is made of high-quality material, which is not affected by increases in air temperature, and also does not change its characteristics over many years, so the chainsaw of this model will look great for decades. Moreover, absolutely all internal spare parts and parts are securely hidden inside the tool, thereby protecting them from corrosion and external influences.

It is also important that this model is equipped with a mechanical chain brake, the main purpose of which is to protect you from accidental chain drop. Since he is able to stop the operation of equipment in seconds. Thus protecting you from accidents.

The Friendship 2 m chainsaw is perfect for working on your summer cottage, as with its help you can easily cope with sawing and harvesting firewood, dry branches and twigs on trees, as well as small-diameter trees.

It is also worth noting that it is equipped with rubber shock absorbers, thanks to which vibration feedback and various vibrations are minimized. This model is a real find for summer residents, farmers, people engaged in professional activities related to working with a saw.

Chainsaw “Friendship – 4” – instruction manual

This model is designed for high-quality and high-speed cutting of wooden materials. This type of chainsaw has an improved and latest modern design.

Moreover, it is quite powerful and at the same time its weight is relatively low. The model also has a quick and easy start system, a quick chain stop system and vibration damping system. Also included are goggles and gloves for your safety.

Chainsaw Friendship 4

The chainsaw has excellent weight distribution, making working with it a real pleasure, as it is efficient and convenient. Thanks to the instant chain stop feature, the tool will not accidentally injure you or people around you.

The model also has a kind of drive coming from the engine (gasoline) with a manual start-up system. And thanks to the anti-vibration feature, you can work comfortably with the saw.

How does the tool factory work?

The chainsaw is equipped with a carburetor two-stroke engine , which is practically its main element. Its power depends on the model of the equipment and its intended purpose.

The chainsaw saw set includes:

• cutting chain;
• sprocket;
• stars;
• tires.

The larger the pitch the headset has, the more powerful and productive it will be, which means the deeper the cut will be . Therefore, the engine should not be inferior to it in terms of power, otherwise the operation of the tool will be inferior.

The chainsaw is lubricated with special oil directly from the second tank located on the hand block. Its mass has such features that the fuel and oil intended for the engine run out at the same time.

We have become familiar with the basic elements of the tool; now it will be easier to understand the reasons why a chainsaw may stop working and how to eliminate them.

Operation, maintenance and repair

To ensure trouble-free operation of the saw, it must be adjusted periodically. The operating instructions supplied with the equipment describe the features of setting up the model. Incorrect configuration will lead to unbalanced operation of the nodes.

How to adjust the carburetor

Failures occur when not enough or too much fuel is supplied, as well as if the proportions when mixing fuel with air are violated.

Carburetor adjustment is carried out as follows:

1. The fuel regulating screw is first turned all the way, and then back (counterclockwise) 1.5-2 turns.
2. Start the engine, warm it up for 1-2 minutes and turn the T screw in one direction or another to ensure its stable operation at maximum speed. The chain should not move along the bar at idle speed.
3. Check and, if necessary, seal the connection between the carburetor and the cylinder.

It is easier to adjust the carburetor using a tachometer, but at home, in most cases, engine operation is adjusted by ear. When both the quantitative and qualitative fuel supply is normal, the engine does not overheat, does not choke, runs smoothly, without sharp sounds. When adjusting, turn the screws slowly, without jerking.

How to set the ignition

Stable operation of the engine is ensured by correctly adjusted ignition - the Druzhba 4 chainsaw in this case will consume a minimum amount of fuel. The saw is ignited thanks to a magneto using a spark plug and a special wire.

To monitor the quality of the spark for igniting the chainsaw, place the spark plug on the cylinder body and pull the starter. If the spark plug is in working condition, a spark will jump between the electrodes. A weak spark will not ignite the fuel; such a spark plug must be replaced.

It is better to replace the contact ignition of a chainsaw with an electronic one. This will eliminate constant problems with its regulation. It is necessary to ensure that the ignition coil mounting screws do not loosen.

Basic malfunctions and their elimination

If you know why the tool malfunctions, you can repair it yourself at home.

When the Druzhba 4 chainsaw engine starts and stalls, the reasons may be as follows:

1. There is not enough fuel in the gas tank. It is necessary to add the mixture according to the instructions supplied with the instrument.
2. The spark plug was splashed with fuel. This prevents a spark from forming. The candle must be removed, dried, and heated on a gas burner.
3. Poor contact between spark plugs and wire. This occurs due to the increased gap (more than 0.5 mm) between the tip of the spark plug and the wire. The spark plugs must be cleaned of carbon deposits with a wire brush and blown with air. They need to be changed periodically.

If engine malfunctions occur at idle, repairing the Druzhba 4 chainsaw comes down to the following:

• replacing the fuel mixture with reducing the amount of oil;
• cleaning the air filter and muffler (due to its clogging, the engine runs but does not develop speed);
• checking the fuel line and replacing the tube if necessary.

If the cutting speed has decreased and the tire is “driving”, pay attention to the sharpness of the saw teeth. A well-sharpened chain is more important than a strong engine.

It is best to take it to a specialist for sharpening or use a machine with a rotary sharpening disk. The bevel of the Friendship saw blade on the bottom edge is 45°, and on the side edge - 60°. The height of the limiting protrusions relative to the chain teeth should be the same and checked after 3-4 sharpenings of the chain.

The reasons why the Friendship saw does not start may be the following:

1. The fuel mixture does not comply with the repair and operating instructions for the model.
2. Manufacturing defects. Repairs are carried out in a warranty workshop.

When assembling, even if the parts fit tightly, you should not use force, for example, hitting them with a hammer. By replacing worn elements, you can restore the functionality of the chainsaw or extend its life.

Ignition system repair

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 algorithm for repairing the ignition of petrol tools Druzhba 4

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.

About safety precautions

Before starting to work with a chainsaw, it is necessary to carry out a number of measures aimed at the safe operation of the device:

• checking the tightness of the fuel system;
• checking the cylinder fastening;
• checking the carburetor is secure;
• checking the muffler is secured;
• checking the tightness of steel fasteners from the outside;
• lubrication of the driven tire sprocket by immersing it in oil for several minutes;
• lubricating the starter cable with lithol-24;
• cleaning the air filter mesh on the carburetor.

When working, you must remember to strictly and compulsorily adhere to the following safety rules:

It is prohibited to carry out work with one hand; work clothes must be durable and include gloves, work shoes, as well as a protective helmet and a special shield; Before refueling, the gas tank cap must be opened extremely carefully, which is due to the possible presence of gasoline vapors; work must be carried out on completely cleared sites, with reliable and strong support; you need to make sure that the chainsaw does not touch foreign objects during operation.

Do not refuel with the engine running. The saw should be transported after the protective cover has been placed on the bar.

Operating instructions for the “Druzhba” petrol saw

This document contains the following information:

1. Device, assembly diagram of the Druzhba chain saw.
2. Technical characteristics of a gas-powered saw.
3. Safety precautions when operating and servicing a chain saw.
4. Preparing for launch.
5. Run-in.
6. Maintenance of the Druzhba chain saw.
7. Malfunctions of the Druzhba chainsaw.

Let's briefly go through the sections:

Chainsaw safety

• do not operate the saw with the air filter removed;
• hold the instrument with both hands;
• use special clothing and protective equipment;
• do not adjust the carburetor if you lack the skills;
• use only high-quality mixture;
• do not work with an empty oil tank;
• do not operate the saw if it is faulty;
• ensure the absence of strangers in the workplace;
• take 10-minute breaks every 45 minutes of work;
• do not use pure gasoline, only when mixing gasoline and oil;
• When replacing the headset, turn off the saw motor.

How to start a chainsaw without a starter

Many people on the Internet are interested in the question of how to start a chainsaw without a starter. Let’s not give hope to our readers; it’s impossible to start a chainsaw, any kind, this concerns not only Friendship 4.

The manufacturer does not provide the ability to start the internal combustion engine in any alternative way other than through the starter. If you dismantle it and instead force the spark plug to give a spark by applying an external rotational force, starting the engine at idle, such an engine will not work for a long time, the chainsaw will be left without a cooling system.

The standard starter of the Druzhba 4 chain saw has a cooling scroll, the impeller of which directs a flow of cold air to the cylinder.

What is good about Friendship-4 and its main disadvantages

The two-stroke MP-1 engine, rated at 4 hp, which gave it the number 4 in its name, developed for this chainsaw in 1953 at the Zaporozhye “Progress”, was, and remains, so easy to repair and maintain that it ensured its success for many decades.

But Druzhba-4 did not deserve its popularity with a single engine. The layout, convenient for long-term work, allows the feller to work standing, in a comfortable position, cutting trees almost close to the ground, and is not repeated in any other saw, except for those that are only its modifications. How many were there? Significant - really one, when the saw acquired a new, more powerful (5 hp) engine, gearbox with a saw chain lubrication system and the name “Ural”. It’s not worth talking about little things like the shape of the tank. And the reduction in weight, which is still hardly the biggest drawback of this design, from 12.5 to 11 kg, cannot be called a significant achievement.

The saw, which received a gold medal at the Brussels exhibition in 1958, was mass-produced until the end of the 90s with minor changes:

• in the 60s, changes were made to the handle fastening;
• in the 80s, the carburetor (“Druzhba-4A”) was replaced and electronic ignition (“Druzhba-4A-Electron” was installed);
• in the 90s, another new carburetor (“Druzhba-4M”) was installed.

Repair and maintenance of Druzhba chainsaw

Reliable spare parts and durable mechanisms of the Druzhba chainsaw are not able to protect the tool from damage. Most often, the causes of tool malfunction are improper handling or simple wear and tear of the mechanisms.

To reduce the risk of premature breakdown of the chainsaw, you should use high-quality gasoline of at least AI-80 grade to refuel it, in which oil for 2-stroke engines should be diluted. The proportion of gasoline and oil should be 1:25, that is, 40 ml of motor oil should be diluted in 1 liter of fuel.

The oil used to lubricate the chain must also be of high quality. Under no circumstances should you pour waste material into the oil tank of your Druzhba chainsaw, otherwise this will lead to damage to the tool’s lubrication system. To prevent the chainsaw chain from subjecting to excessive friction, use only fresh oil from trusted manufacturers.

It should be noted that the use of a high-quality fuel mixture and lubricant does not guarantee the constant uninterrupted operation of the Druzhba chainsaw. However, even if you discover a malfunction, you should not get upset right away. Some breakdowns are quite easy to fix with your own hands. Below we list typical malfunctions of domestic tools and ways to eliminate them yourself.

Adjusting the Druzhba chainsaw carburetor

1. To find the highest engine speed in idle mode, you must slowly turn the screw marked “L” clockwise. Once you find the maximum RPM, turn the same screw back ¼ turn. If after this the chain on the bar continues to rotate, then turn the screw marked “T” counterclockwise until the saw element stops completely;
2. Turning the screw marked “H” will allow you to adjust the required power and speed. To do this, you need to connect a tachometer to the Druzhba chainsaw and by turning the “H” screw, find the optimal number of revolutions indicated in the instructions. Immediately after this, turn screw “H” ¼ turn counterclockwise;
3. Then you need to fine-tune the engine idle speed. To do this, screw “T” should be turned until the saw chain begins to rotate. Immediately after this, turn the screw “T” in the opposite direction until the chain stops completely.

Carburetor adjustment carried out according to the instructions will allow you to reduce the fuel consumption of your Druzhba chainsaw and protect its parts from excessive wear.

How to set the ignition on a Friendship chainsaw?

To properly repair a tool, you need to carefully study its operating instructions. As the repair instructions for the Druzhba chainsaw indicate, to install the ignition, you need to remove the cover to which the starter is attached and turn the magneto so that the marks on it and the adapter coincide. After this chainsaw, friendship will be much easier to make.

Advantages and disadvantages

Advantages of petrol saws of the Druzhba series:

• the use of aluminum alloy for the manufacture of the body;
• removable structural elements fixed with threaded connections;
• high power and increased engine torque;
• when the chain jams, the motor does not stop;
• the use of gasoline with an octane rating of less than 80 is allowed;
• the design of the handles allows you to saw wood while standing;
• high build quality (especially products of early modifications);
• chrome plating of the working surface of the cylinder is provided.

Equipment disadvantages:

1. there is no emergency stop button for the engine; when the speed drops, the shaft is disconnected from the chain gear by a centrifugal clutch;
2. the heavy weight of the saw, making it difficult to carry the product;
3. spontaneous loosening of threaded connections;
4. high noise level during operation and oil emission from the exhaust pipe;
5. the use of an internal combustion engine imposes restrictions on the use of the tool indoors.

Device

The main parts of the chainsaw are as follows:

• engine;
• sawing apparatus;
• frame with handles;
• gas tank

The engine is a single-cylinder two-stroke carburetor. Cooled by air flow created by a centrifugal fan. The engine and sawing apparatus are independent units, connected into 1 unit with flange fasteners and secured with a clamp.

When the fuel tap is opened, fuel enters the diaphragm carburetor, which ensures uninterrupted supply to the engine at any angle of inclination and strong vibration. The design of the chainsaw does not allow the engine to stop if the chain gets jammed in the barrel while cutting wood.

The handles are located high, which provides the following capabilities:

• do not bend over while working and get tired less;
• work in deep snow conditions;
• increase user safety.

Adjusting the Druzhba chainsaw carburetor

The main reasons for the need to urgently adjust the carburetor of Druzhba brand chainsaws include:

• interruptions in fuel supply;
• excessive volumes of fuel supplied by the carburetor;
• failures in the process of preparing a mixture of fuel and air - in these cases, the fuel system sucks in too much or not enough air.

Its repair instructions will tell you about the procedure for adjusting the carburetor of a Druzhba chainsaw. The operator’s action algorithm should be as follows:

1. On a saw with the engine turned off and cooled down, the screws responsible for the amount of fuel and air must be turned alternately until they stop. After this, each of the screws must be turned 2-3 full turns in the opposite direction;
2. After warming up the power unit, by ear or using a tachometer, you need to set the screw positions that will ensure the most stable operation of the engine;
3. As a result, the Druzhba chainsaw motor should operate quietly, without interruptions or jerks, and the chain should not rotate arbitrarily on the bar.

To reduce the frequency of carburetor adjustments, you need to fill the chainsaw with a properly prepared fuel mixture. The proportion of gasoline and oil for the Friendship chainsaw should be 1:20, that is, at least 50 ml of motor oil must be diluted in 1 liter of fuel.

User manual

When working with the Friendship saw, you must follow the operating rules:

• Start-up and operation is prohibited with a damaged or removed air filter;
• the instrument is held with two hands;
• To protect the operator, special clothing and glasses are used;
• at the moment of starting, the saw chain should not touch the ground, stones or other objects;
• It is not allowed to saw wood without filling the tank with oil;
• It is strictly forbidden to refuel the saw with pure gasoline;
• when operating the saw for a long time, it is necessary to take breaks to cool the motor (every 40-45 minutes);
• The tightness of threaded connections is periodically checked;
• If parts of the saw are damaged, operation of the tool is suspended.

Before using the saw, you should read the instructions from the manufacturer. To make a fuel mixture, you need to prepare gasoline and special oil. Half the volume of prepared gasoline is poured into a clean container, then lubricating fluid is added and mixed thoroughly. Then the remaining gasoline is poured into the mixture, the solution is further mixed and filled into the tank. When running in the engine (after replacing the rings), it is recommended to introduce additional oil to ensure the running-in of the rubbing surfaces.

When felling wood, a cut is first made, located on the side where the trunk should fall. Then the trunk is sawed on the other side; There should be no unauthorized persons within a radius of 50 m from the tree being cut down. The operator moves from trunk to trunk with the saw running at idle speed (without chain rotation) or with the engine off. The operating instructions do not allow sawing of trunks tied into logs or stacked.

During operation, it is necessary to adjust the engine idle speed and adjust the carburetor to achieve maximum power. The equipment requires adjustment of the clutch, which overheats during prolonged operation and loses its original characteristics. Since the saw chain stretches during operation, it is necessary to adjust the tension of the element. A correctly tensioned chain moves along the bar by hand and has no sagging in the lower branch.

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.

Causes of malfunctions and ways to eliminate them

Almost every chainsaw owner has at least once encountered the fact that the tool either does not start at all when you press the gas, or starts and stalls after a while. There can be many reasons for a device to malfunction. Some of them are quite simple and easy to fix. Therefore, it is worth studying the main reasons so that in the event of a basic breakdown, you do not take the tool to a chainsaw repair service.

Why does a chainsaw start and immediately stall?

There may be several reasons for this:

1. There is not enough fuel in the gas tank. If the tool stops working immediately after the factory, then first of all you need to check the presence of fuel in the gas tank. If it is not enough, then you need to add the fuel mixture, which is prepared strictly according to the instructions included with the tool. Chainsaw fuel consists of gasoline with the highest possible octane number and oil, the brand of which must be specified in the technical passport of the tool.
2. Poor contact between spark plugs and high-voltage wire. The gap between the spark plug tip and the wire should be no more than 0.5 mm. If carbon deposits have formed on the candle, it must be cleaned and dried. Experts recommend periodically updating spark plugs, even if the old ones are still working properly.
3. Pouring a candle. A large amount of fuel collects between the spark plug electrodes, so if the spark plug is flooded, a spark will not form. To fix such a breakdown, just remove the spark plug and dry it. It would be useful to heat it using a gas burner.
4. Carburetor jet or fuel filter is dirty. It is quite easy to clean the gas filter yourself, but it is better to entrust cleaning the carburetor to specialists.

The chainsaw malfunctions at idle speed

The cause of this malfunction may be a dirty muffler. Therefore, in order for the tool to work properly, sometimes you just need to clean the muffler of exhaust tar deposits. Quite often, the air filter in the tool becomes clogged, the air flow into the system becomes clogged, and this leads to the device stalling at idle.

Most common faults

1. The engine does not start. Check for a spark at the spark plug electrodes. Make sure there is no damage to the wire insulation, clean or replace the spark plug if necessary.
2. Make sure the fuel tank is tight; interruptions in engine operation are often caused by moisture and condensate getting into the fuel mixture.
3. Adjust the carburetor
4. The most common cause of overheating is a lack of lubrication. Correct the problem.
5. Check the serviceability of the muffler. Its design is quite simple; repairs are possible at home.
6. The reason may be a malfunction of the ignition module, as well as a violation of the gap between it and the magnetic circuit in the flywheel. Gap length – from 0.2 mm. up to 0.5 mm.. This value is set using a special gasket, which is located between the flywheel boss and the ignition module. The broken module is replaced. In addition, you can replace the spark plug.