Chainsaw Druzhba - characteristics, do-it-yourself repairs, homemade options

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.

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.

Why is Friendship 4 not gaining momentum?

Starting the Friendship 4 chainsaw is the most technically complex process in which all systems of the chainsaw are involved. But if you manage to start the engine, but when you press the gas handle the saw does not gain momentum, there may be many reasons:

• Malfunctions in the engine: the service life has expired, the cylinder or piston rings are worn out, rusted or scored;
• Malfunctions in the ignition system: the spark plug or coil winding has failed - the spark is weak or does not form at all and cannot ignite the fuel mixture;
• Malfunctions in the carburetor: incorrect settings, unbalance of the carburetor cover mounting bolts;
• Depressurization of the fuel system, engine crankcase;
• There is a lot of carbon deposits in the muffler and exhaust gases are difficult to release.

Eliminating the causes of ignition system malfunctions

1. Unscrew the spark plug, dry it if it is filled with fuel, replace it with a new one if it has strong black carbon deposits.
2. Make sure that the coil is not pressed tightly against the magnets, there should be a distance of up to 0.2 mm and free movement. If this is not the case, secure the coil to the required distance.

If these manipulations do not help, you can independently check the entire spark plug block for spark supply through the power cable. If there is a spark, but you cannot understand the cause of the problem, it is better to take the chainsaw to a service center.

Eliminating the causes of malfunction of the carburetor unit

1. Correctly adjust the chain saw carburetor. Read above how to do this.
2. Remove the carburetor cover, check the presence of all parts and their movement inside the block, secure the cover in place by evenly tightening the fastening screws, checking that the carburetor cover fits snugly.

Adjusting the ignition of a friendship chainsaw

With a properly adjusted ignition, the Druzhba chainsaw will operate on the very minimum amount of gasoline required by its engine. Ignition occurs as a result of synchronous operation of the magneto, spark plug and corresponding wire, with the ignition coil being correctly and securely fastened. To check the spark strength, place the spark plug on the cylinder body and start the starter. If the spark is weak, then such a spark plug must be replaced. And if constantly checking the spark plugs is not part of your plans, then it is recommended to replace the contact ignition of the Druzhba saw with an electronic one.

Important! Malfunctions in the operation of the Friendship chainsaw motor are usually caused by malfunctions in the ignition system, and contact ignition itself is extremely sensitive. If a gas-powered saw has a non-contact electronic ignition, then most often the fault is caused by a burnt-out thyristor in the magneto. Recommendation: replace it with an imported one.

Carburetor adjustment and muffler cleaning

If excess fuel is eliminated, but the breakdown is not corrected, then the carburetor may not be adjusted.
To fix this, follow these steps in strict order:

• turn the fuel screw until it stops;

• unscrew it three turns. No more, no less;

• screw the propeller firmly;

• unscrew it already two strict turns;

• Seal with sealant or wrap thin sheet metal around the adapter coupling.

Everything that must be firmly and tightly connected. The quality of the chainsaw depends on this.

There are times when the chainsaw motor only works at low speeds and stalls at high loads. A similar problem may indicate a clogged muffler.

The muffler spark arrester can become clogged for several reasons:

1. Using low-quality oil;
2. The fuel mixture has a high oil level;
3. Using oil not intended for such engines.

In any of these cases, you need to remove the muffler and clean it well with various detergents. After that, dry it with a hairdryer.

Read here how to choose the right chainsaw.

The Druzhba chainsaw is a mechanized tool that is used to cut thick branches, clearing power line routes, as well as felling trees. Whether a given instrument is of the highest quality or not is difficult to answer. Some consider him a reliable assistant, while others do not like him, as he is clumsy and capricious. Nowadays, this chainsaw model is popular not only in Russian markets, but also outside the Russian Federation. This unit is available in almost every family living in villages and villages. Therefore, whether it is reliable or inconvenient is impossible to answer. But like any other tool, this chainsaw tends to break. Is it possible to repair a Druzhba chainsaw yourself at home? If you wish, you can. But, if it is carried out in specialized workshops, then this repair will result in a good amount.

What can be done to extend the life of a chainsaw without repairs?

Repair of the crankshaft main bearing has to be carried out quite often, since this is the most vulnerable point of this model of chainsaw. As soon as it becomes faulty, the ignition begins to go astray, which leads to unpredictable operation of the tool. With such a breakdown, in some cases it is almost impossible to start the chainsaw. But in other cases it simply cannot be drowned out in any way. This model was recently equipped with a button that forcibly stops the operation of the unit. Craftsmen who are well versed in this have installed such buttons on their units themselves much earlier. Chainsaw Friendship is a capricious tool. Under intense load, it has a considerable list of failures, including broken connecting rod, jamming of the piston, as well as loss of spark and gearbox malfunction.

The presence of contact ignition in a chainsaw also causes a lot of trouble, since it is sensitive to various brands of not only oil, but also gasoline. Therefore, to prevent this problem from leading to tool repair, experts strongly recommend replacing the contact ignition with an electronic one. This model of chainsaw should be constantly adjusted and tuned. If problems with the carburetor are quite common, then you can solve it by bending the gasoline valve inside. As a result, the amount of fuel that enters the engine is limited.

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.

Forest exploitation and forest transport

Monday, 06/17/2019, 12:50

catalogue of articles

Chainsaws "Druzhba-4" and MP-5 "Ural-2" (Part 1)

The Druzhba-4 chainsaw, like the MP-5 Ural-2, is a specialized power tool designed primarily for felling trees in flat areas (Fig. 4.7). The Druzhba-4 chainsaw has the same layout as the MP-5 Ural-2 saw. The main components of the Druzhba-4 chainsaw are the engine, clutch, gearbox, frame and sawing apparatus. The engine of this saw differs from the engine of the MP-5 "Ural-2" chainsaw in its smaller size, power, and crankshaft rotation speed. The engine power system uses a KMP-100A carburetor, which differs from the carburetor of the MP-5 "Ural-2" chainsaw in the type of throttle and the absence of a pump. The operating principle of this carburetor is similar to that described above. The driving part of the Druzhba-4 chainsaw clutch is connected to the driven part by spring rings. The gearbox of the Druzhba-4 chain saw is structurally simpler and is distinguished by the absence of a built-in oil pump and a tank for lubricating the saw chain. A plunger pump is placed in the frame stand, and the stand simultaneously serves as a reservoir for oil that lubricates the saw chain and guide groove of the bar. The lubrication lever is mounted on the left handle of the frame.

Rice. 4.7. Chainsaw "Friendship-4":

• 1 - sawing device
• 2 - gearbox
• 3 - frame with handles
• 4 - gas tank
• 5 - engine

The Taiga-214 chainsaw is a universal-purpose power tool (Fig. 4.8). With its help, you can carry out felling trees, trimming branches and bucking logs, as well as preparatory and auxiliary work at the cutting site. The characteristic features of this saw are the absence of a gearbox and the low position of the handles. Elimination of the gearbox significantly reduced the weight of the saw and increased the sawing speed. Increasing the speed resulted in increased sawing performance and reduced pushing forces. The front handle of the frame surrounds the engine on both sides, allowing you to grab the saw and quickly move it from the felling position to the bucking position or to an intermediate position in between for trimming branches.

Rice. 4.8. Chainsaw "Taiga-214":

• 1 - sawing device
• 2.4 - front and rear handles
• B - engine
• 5 - starter

Removable starter , used to start the engine, consists of a housing, a drum, a drum roller, a coil spring and a ratchet. A rope is wound in the groove of the drum, one end of which is fixed in the groove of the drum, and the other in the rubber handle. When the rope is pulled, the roller rotates and, through the pin and screw slots, rotates and pushes the drive ratchet forward, engaging it with the driven ratchet mounted in the engine flywheel hub. When the flywheel rotates, the crankshaft rotates and the engine starts. After starting the engine, the starter is removed from the saw. The saw is controlled using the carburetor throttle control lever: when pressing the lever to the handle, the carburetor throttle opens, while the supply of the working mixture to the cylinder increases, the engine speed and power increase. Stop the engine by pressing the ignition switch button.

Model range of chainsaws Druzhba

The advantages of the Druzhba chainsaw, in addition to those mentioned above, are that it cuts smoothly and accurately, is highly productive and all the parts are in a durable case. Its disadvantages include significant weight - more than 12 kg with dimensions of 86.546x50 cm and a cable starter.

The main difference between modifications of the Friendship chainsaw is engine power:

• Friendship 2 has a power of 2 kilowatts, manual start and, unlike the 1st model, an element for chain braking.
• Druzhba 4, which received “gold” at the World Technology Exhibition in Brussels in 1958, has almost one kilowatt more power, sawing effortlessly, with shaft revolutions of more than five thousand, a half-meter log in one minute.
• Friendship 4M-electron, having a contactless electronic ignition system, uses the engine resource more efficiently, with almost the same power - 3 kW. The cylinder's chrome coating adds wear resistance, and rubber gaskets reduce overall vibration. In modification 4A, an oil pump is installed for forced lubrication of the chain.

Like any other technical device, the Druzhba 4 chainsaw requires constant carburetor adjustment, attention, regular care and preventive maintenance. At least once a year it is necessary to fine-tune the Druzhba 4 carburetor, including its adjustment.

Repair instructions for the Druzhba-4 carburetor

The most common causes of failure of the KMP-100 carburetor:

1. Contamination of fuel and air channels, nozzle holes.
2. Loss of tightness.
3. Failure of the membrane - rupture, loss of elasticity, etc.

In the first case, the carburetor is disassembled. The parts are laid out on a clean cloth, remembering which one comes from where. The body and parts are washed in gasoline. The channels and holes of the jets are purged and washed.

The tightness is restored by disassembling the carburetor, changing the gaskets or using a gas-resistant sealant.

If the membrane fails, it is replaced with a new one.

Before repairing and adjusting the carburetor, you need to make sure that fuel is properly supplied to it from the gas tank.

The Druzhba-4 chainsaw has a tank located on the handles and has a faucet with a filter, which can become clogged. You need to remove the fuel hose from the carburetor fitting and make sure that gasoline flows fully.

This carburetor can no longer be repaired. better to replace with a new one

Why does it overflow

If there is too much fuel in the combustion chamber, the spark plug may be flooded, the spark will disappear and the engine will not start.

If the engine does start, the engine cannot develop speed because there is not enough oxygen to burn the fuel.

If the overflow is small and the engine is running, there will be excess fuel consumption.

Often overflow occurs due to the adjustment screws being unscrewed too much, especially the second one. The problem is solved by adjusting the carburetor of the Druzhba-4 chainsaw.

The second reason is the failure of the membrane and the valve associated with it. A broken membrane and valve do not regulate the flow of fuel, and it comes in excess.

A one-time overflow when starting a cold engine can be caused by excessive pumping of fuel by the enrichment button (choke or primer button).

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.