Trimmer Coupling. Malfunctions, Causes, and Remedies
1) Malfunction of the trimmer: At idle the knife is almost always spinning, in front of the motor there are other sounds, and the trimmer mows normally. Fault Trimmer same as the trimmer.
Causes of failure: The trimmer clutch spring has burst.
DIY repair of the trimmer: Replace the burst clutch spring with a new one (for details, see below “How to remove the clutch on the trimmer”). Or, if only a hook is broken off on a spring, you can heat the spring with a torch, bend one ring to create a new hook and harden the spring (such a clutch spring can work even for several years). Repair Trimmer do it yourself is similar to repair trimmer.
How to remove the clutch on a chainsaw?
- Chainsaw device
- Device motor chainsaws
- Carburetor and fuel system
- Ignition system and starter powerplant chainsaws
- Chainsaw Clutch
- How to remove the chainsaw grip?
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.
It is worth noting that all chainsaws are a classic device, driven by a gasoline engine.
In the device, chainsaws have found the use of single-cylinder engines operating on high-octane gasoline. The 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 in the presence of severe 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 to start the power saw of the chainsaw, a chain tensioning mechanism, an ignition system, and an exhaust silencing system. Also, the design of the chainsaw includes the so-called emergency brake, the operation of which allows in an emergency to instantly disconnect the power unit of the chainsaw from the drive sprocket to prevent injury to the person operating the device.
In modern chainsaws, a two-stroke, the 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:
- ignition module;
- 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, under challenging conditions for the power plants of the device, it is necessary to ensure proper 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.
The carburetor in the device of the power plant is designed for the preparation and supply to the cylinder of the combustible mixture. Most often, carburetors produced by manufacturers such as Walbro, Zama and some others are used in the chainsaw device. A unique filter is mounted on the carburetor on top for cleaning up the air into the carburetor. The fuel system in its purest form consists of a tank, a filtration element, and a hose for feeding fuel. As a rule, the fuel tank is sufficient for operation within 30-40 minutes.
To fill the tank while the device is running 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, atmospheric air must be introduced into it to prepare a combustible mixture in the carburetor. The incoming air is cleaned with a different air filter. As a rule, two filters are installed in the chainsaw design: coarse filter and excellent filter. 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 as a filter element uses a thin foam, nylon mesh or some other materials. The chainsaw filter requires regular cleaning.
Ignition units, which do not require adjustment and cleaning. The ignition system includes a flywheel with magnets, a module with an automatic mode, a spark plug, and a high-voltage wire.
The starter mounted on the device serves to start the saw engine by cranking the crankshaft.
The starter mechanism includes the following elements:
- cable with handle;
- return spring.
When carrying out a sharp pulling of the cable, the starter ratchet engages with 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.
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 parts 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 stops, thus avoiding breakage of the power plant and the mechanisms transmitting movement to the chain. Often enough, adhesion due to intensive use is required to be prevented and repaired. For this purpose, disassembly of the clutch.
The clutch drum is also a leading asterisk.
This structural element is consumable, and this, in turn, requires regular replacement or repair.
The main reason for the failure of this node is the wear of the sprocket teeth. If the drum is monolithic, 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 wreath, 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 practically every person can carry it out with the appropriate tools. Almost every model of this tool has its 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. It 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 relax the chain and tire after unscrewing the nuts securing the brake cover, after which the cover is deleted.
At the second stage, the dismounting of the guide rail and the chain is carried out, and the pollution is removed.
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 the exhaust port is blocked, a piece of rope is lowered into the cylinder, which prevents further piston movement. After the repair, the line 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 grip. 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 chainsaws is used.
After unscrewing the nut, you need to disassemble the clutch and inspect the drum with the drive sprocket for wear. Then, after the inspection of the drum and gear, a review 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:
- On some modifications and models of chainsaws, a washer is placed between the clutch and the drive sprocket cup. 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.
- Some models of oil pump drives have a special spring. It transmits rotation from an asterisk to the oil pump drive. It is essential to install this spring when assembling the device correctly. If improperly mounted, the oil pump stops the flow of oil to lubricate the chain. What can lead to costly repairs.
After 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 bus mechanisms.
Chainsaw coupling. malfunctions, causes and remedies
- Chainsaw malfunction: The chain runs almost constantly (the engine, however, may not work stably). Causes of failure: The clutch spring has burst. Do-it-yourself repair of a chainsaw: Replace a burst clutch spring with a new one (for details, see “How to remove the chainsaw clutch” below). Husqvarna chainsaws have one clutch spring and two weights, while Stihl chainsaws have three clutch springs and three weights (cams, sectors). If you cannot find the clutch spring itself, you will have to change the entire clutch.
- Chainsaw malfunction: The chain is spinning almost always, sometimes there are other sounds in the clutch. Causes of malfunction: The clutch cam splintered (due to overheating) and the clutch spring fell off. Overheat evidenced blue clutch cams. Overheating right up to a clutch breakage can occur if the chainsaw is operated with the chain brake or a blunt chain engaged.