How to remove the clutch on a chainsaw

Often, people who use chainsaws in the process of maintenance raise the question of how to remove the grip on a chainsaw. The fact is that this node of the chainsaw mechanism requires constant monitoring of working capacity, which, in turn, requires periodic disassembly for preventive maintenance and repair.

The scheme of the chainsaw device.

Chainsaw device

It is worth noting that all chainsaws are a classic device, driven by a gasoline engine.

Electronic ignition scheme chainsaw.

In the device, chainsaws have found the use of single-cylinder engines operating on high-octane gasoline. Gearbox power unit has not. It is a single-stage transmission, which sets in motion the chain. The simplicity of the design is the key to reliability and dependability of the tool, even under difficult operating conditions.

In addition to these nodes, the chainsaw design includes an air purification system that is fed to the engine to prepare the combustible mixture, a tire with a saw chain installed on it, a starter that provides power for starting the power saw of the chainsaw, a chain tensioning mechanism, an ignition system, an exhaust silencing system. In addition, the design of the chainsaw includes the so-called emergency brake, the operation of which allows in an emergency situation to instantly disconnect the power unit of the chainsaw from the drive sprocket to prevent injury to the person operating the device.

Device motor chainsaws

Types of spark plugs for chainsaws.

In modern chainsaws, a two-stroke, single-cylinder carburetor-type power plant is installed.

The engine consists of several systems and components that make up a single whole. The design of the engine can be divided into several elements that ensure its functioning:

• flywheel;
• clutch;
• ignition module;
• muffler;
• special bush for carburetor mounting.

Chainsaw engines are high-speed. The maximum number of revolutions of the power plant is 13,500 revolutions per minute. This requires the use of high-quality oil when lubricating the engine, which is added to the fuel mixture.

Since the operation of chainsaws is carried out, as a rule, in difficult conditions for the power plants of the device it is necessary to ensure good cooling. The engines used to install the chainsaw, are power plants, equipped with a forced cooling system. For this purpose, an impeller is mounted on one of the crankshaft axles in a closed housing. Due to the rotation of the impeller air is supplied to cool the cylinder of the power plant through the appropriate duct.

Carburetor and fuel system

Fuel system for chainsaws: 1 - fuel filter, 2 - carburetor, 3 - manual pre-priming pump.

The carburetor in the device of the power plant is designed for the preparation and supply to the cylinder of combustible mixture. Most often, carburetors produced by manufacturers such as Walbro, Zama and some others are used in the chainsaw device. A special filter is mounted on the carburetor from above for cleaning up the air into the carburetor. The fuel system in its simplest form consists of a tank, a filter element, and a hose for feeding fuel. As a rule, a fuel tank is sufficient for operation within 30-40 minutes.

To fill the tank with the device in operation with air, its cap has a breather that lets air into the tank and prevents fuel from flowing. If the breather is clogged with debris, the engine stops. At the end of the free-flowing hose, a fuel filter is installed. Fuel injection occurs due to the operation of the pump located inside the carburetor.

When the power plant is in operation, the flow of atmospheric air into it is required to prepare a combustible mixture in the carburetor. The incoming air is cleaned with a special air filter. As a rule, two filters are installed in a chainsaw design: a coarse filter and a fine one. The pre-filter has several elements and prevents large impurities from entering the engine. The fine filter cleans the air from dust particles. In some models, the flywheel impeller is used as a cleaning element, which cleans the air flow from large impurities due to centrifugal forces. In the manufacture of fine filters, diffuse foam rubber, nylon mesh or some other materials are used as filter elements. The chainsaw filter requires regular cleaning.

Ignition system and starter powerplant chainsaws

Scheme of a two-stroke engine chainsaw.

Today, gasoline-powered saws are equipped with electronic ignition units that do not require adjustment and cleaning. The ignition system includes a flywheel with magnets, a module having an electronic system, a spark plug, and a high-voltage wire.

The starter mounted on the device serves to start the saw engine by turning the crankshaft. The starter mechanism includes the following elements:

• drum;
• cable with handle;
• housing;
• return spring.

When carrying out a sharp pulling of the cable, the starter ratchet engages the crankshaft teeth, which leads to its turning. The return spring is designed to return the cable to its original position. To start the power plant requires a certain effort, since the engine starts only at a certain speed of rotation of the crankshaft.

Chainsaw Clutch

The design of chainsaws is equipped with a centrifugal clutch, which operates in automatic mode, in full dependence on the rotational speed of the engine crankshaft.

At low speeds, elements installed in the clutch basket and having special inserts are attracted to the center of the shaft by springs. This position of the elements prevents the transfer of rotational motion from the crankshaft to the sprocket. When a certain number of revolutions of the power plant is reached, the elements with special inserts diverge and are pressed against the clutch drum, transmitting the rotation to the chain. The main feature of this clutch is that it starts to slip when the saw chain is stopped, thus avoiding breakage of the power plant and the mechanisms transmitting movement to the chain. Quite often, the clutch as a result of intensive operation is required to be prevented and repaired. For this purpose, disassembly of the clutch.

How to remove the chainsaw grip?

The clutch drum is also a leading asterisk.

This structural element is consumable, and this, in turn, requires regular replacement or repair.

The position of the file when sharpening the chainsaw chain.

The main reason for the failure of this node is the wear of the sprocket teeth. If the drum is monolithic, then in the process of operation the chain cuts through an asterisk. Such a drum must be replaced. On some devices, the drum has a replaceable crown and during the repair it is replaced, and the drum, while maintaining the normal state, is operated further.

In case of need repair chainsaw raises the question of how to disassemble the clutch. In the presence of a service center, it is better to contact the specialists, but in the absence of the latter, the disassembly and repair procedure can be carried out with your own hands. This operation is simple and with the right tools, almost every person can do it. Almost every model of this tool has its own nuances in disassembling the clutch, but the general sequence of actions is the same for any models.

The first step is to remove the chain brake cover. For this purpose it is required to pull the handle towards yourself. This is done so that the tape does not come into contact with the clutch cup. After that, the nuts securing the cover and the chain tensioner are loosened.

Loosening the tensioner allows you to loosen the chain and tire. After unscrew the nuts fastening the brake cover, after which the cover is dismantled completely.

At the second stage, the dismounting of the guide rail and the chain is carried out, the removal of dirt.

The next stage of disassembly is the inversion of the cylinder head candles. Then the piston is fixed in the cylinder. For this purpose, the crankshaft rotates and, after blocking the exhaust port, a piece of rope is lowered into the cylinder, which prevents further piston movement. After the repair, the rope is pulled out of the second end to the outside.

The fourth stage of disassembly is the direct disassembly of the clutch. First you need to unscrew the nut on the clutch. It should be remembered that this one has a left-handed thread; when unscrewing it, the key must be rotated clockwise. For work the key which is included in the complete set of accessories of the chainsaw is used.

After unscrewing the nut, you need to disassemble the clutch and inspect the drum with the drive sprocket for wear. Then, after inspection of the drum and sprocket, an inspection of the condition of the needle bearing is carried out. Replace worn parts if necessary.

The assembly tool is carried out in reverse order.

There are several nuances that you need to know when repairing clutch:

1. On some modifications and models of chainsaws between the clutch and the cup of the drive sprocket is placed a washer. In the case of disassembly of this element requires installation of the washer in the position in which it was previously. This washer can sometimes be installed between the engine and the cup.
2. Some models of oil pump drives have a special spring. It transmits rotation from the sprocket to the oil pump drive. It is very important to correctly install this spring when assembling the device. If improperly installed, the oil pump stops the flow of oil to lubricate the chain. What can lead to costly repairs.

After the repair work, before using the chainsaw for its intended purpose, it is necessary to check the operation of the oil pump and its supply of oil for lubricating the saw chain and guide rail mechanisms.