How to change the cable on a chainsaw
Chainsaw clutch replacement and repair
Chainsaw clutch malfunctions are one of the most common failures of this technique. The question of how to remove the clutch on a chainsaw at home correctly and not harm the tool is thought not only by inexperienced technicians, but also by specialists who have repaired it more than once. This is due to the fact that the clutch is an important key element of chainsaws of any power class and brand, on which their serviceable, long-term and successful operation depends.
In cases where gasoline cutters start to start badly, slip instead of starting, checking the clutch for faults is mandatory, recommendations regarding which will be presented further.
How to remove a clutch from a chainsaw: a detailed report
The clutch repair process consists of the following operations:
- dismantle the chain set, air filter flaps and the clutch itself;
- lock the crankshaft. for this it is enough to simply unscrew the ignition cut;
- unscrew the clutch with a special wrench with strong movements clockwise or counterclockwise (different saw models can have both left and right threads). Usually the tool for removing the clutch is included with the chainsaws;
- go to disconnecting the drum and sprocket;
- if, when inspecting the clutch, one or more cracked springs were found (there may be several of them, for example, for Husqvarna chainsaws. 3 units). you need to replace the broken spring with a new one;
- assemble the clutch on the chainsaw, put it in place and screw it in. Remember that the crankshaft must still be stationary;
- mount the removed parts on the saw in the reverse order to disassembly;
- fix the clutch. move the auxiliary brake handle forward, start the device and carefully remove from the inertial brake.
The device and principle of operation of the clutch of chainsaws
Modern chainsaws are equipped with centrifugal clutches. This means that their work entirely depends on the torque of the motor, which the saw gives out at a particular moment in time.
Its main structural elements are:
The principle of operation is as follows. When the saw is started, elements that move freely in the radial direction are pulled together by springs to the shaft axis. In this case, the torque does not go to the drum, which means to the sprocket and the guide. At the moment when the centrifugal force prevails over the force potential of the springs, the clutch elements weaken and compress at the inner part of the drum, initiating its torsion. Together with it, the rotational cycle goes to the sprocket and the tire-chain set itself.
The main advantage of this type of clutch is its slippage when the cutting part is suddenly braked, which does not stop the engine. As a result, the “heart” of the saw. the motors remain safe and sound.
Clutch repair: the nuances of the process
When servicing clutches yourself, you need to know that:
- several saws have a washer that sits between the sprocket and the clutch and the sprocket and the motor. Consider this when repairing;
- the special spring of the oil pump drive must not be damaged during disassembly, and must also be returned to its original position. Otherwise, the chain will receive less lubrication or no longer lubricate at all.
The tool that has been repaired must be checked for the reliability of the bolt ties, the supply of lubricant to the chain and the serviceability of the motor (it should turn on smoothly and work smoothly). Only then can it be exploited.
How to remove the clutch on a Stihl 180 chainsaw
Removing and disassembling the engine
The engine is held in place by 4 screws installed on the bottom of the Stihl 180 chainsaw. To remove them, unscrew them, then carefully remove the engine from the seat and the rubber pipe of the carburetor.
To disassemble the engine, 4 crankcase screws are unscrewed, and it is removed, then you can remove the crankshaft assembly with oil seals, bearings and piston rings.
Removing bearings and seals usually does not require additional tools, but if the bearings were pressed onto the shaft with force, then a special puller will be needed for dismantling.
To remove the piston from the connecting rod, you will need to remove the retaining ring from the seat using a thin screwdriver, then the piston pin is squeezed out from the opposite side, after which the piston is retracted to the side.
Clutch device, principle of operation
In order to successfully disassemble this unit, you will need a chainsaw clutch puller. But before we look at how to use it, we will study the features of the device of this functional part of the power unit.
Please note that when developing modern chainsaws, manufacturers most often resort to using a centrifugal clutch. And this suggests that the tool and its operation depend on the stock of torque that the equipment produces here and now.
The main structural details of this unit include:
As for the principle of operation, everything is simple here.
How to Replace a Starter Rope on a Stihl Chainsaw.The Easy Way by Bobby
- As soon as the chainsaw is in working mode, the clutch springs will pull all freely moving elements (move in the radial direction) towards the axis.
- At this moment, no torque will be transmitted to the sprocket guide.
- As soon as the centrifugal force rises above the force potential of the spring, all freely moving attracted elements will weaken and compress inside the drum, which will start it (it will start spinning).
- Rotation will transfer to guide bar and main sprocket.
It is on this principle that the centrifugal clutch works, which has several advantages over its other varieties. Among them is the lack of engine stop when the cutting element is suddenly braked (that is, the clutch slips). Due to this feature of the mechanism, the main unit of the chainsaw remains unharmed.
Please note that this type of clutch will work automatically. Its functioning depends on the number of revolutions of the engine. Moving elements inside the drum will be attracted to the shaft (its center) even at minimum RPM. This plays an important role in preventing serious tool breakage. When this mechanism fails, then it becomes necessary to figure out how to remove the clutch on a chainsaw.
Reasons why you need to disassemble the clutch:
- Defective or burst spring;
- As a result of loads on the chainsaw and wear of parts, the spring has left its place;
- Chips on the clutch plate;
- Wear of parts.
Stihl chainsaw clutch repair review
Chainsaw clutch replacement review
Removing the starter
At the next stage, the upper housing cover is removed and the 4 starter mounting screws are loosened, after which it is necessary to remove the oil tank and fuel barrel covers. The starter is removed quite simply and there should be no problems.
After removing the starter, the opened inner cavity of the chainsaw must be cleaned, since usually there is a large amount of compressed small sawdust on the body under the starter.
Dismantling and cleaning the muffler
If the engine works fine at low speeds, and at high speeds it starts to stall, the reason may lie in the spark arrester of the muffler, clogged with combustion products.
- remove the muffler;
- disassemble (there are also non-separable models);
- remove carbon deposits using detergents;
- dry with a hairdryer;
- put in place.
Dry cleaning is unacceptable, as the soot contains carcinogens, the inhalation of which is hazardous to health. After removing the muffler, the outlet is closed with a clean cloth.
Interruptions in the operation of the chainsaw signal a possible clogging of the muffler
To avoid clogging of the muffler, it is necessary to monitor the composition of the fuel mixture. The amount of oil should not exceed the standards recommended by the manufacturer. Poor oil quality also negatively affects engine performance.
Do-it-yourself chainsaw repair: analysis of major breakdowns and methods for their elimination
It would seem, why does a chainsaw need a summer resident who grows vegetables and fruits, or the owner of a country house who has a small garden and several flower beds? The question disappears when there is a desire to build a bathhouse, update a greenhouse, knock down an old business, or just make a bench for relaxation. Unfortunately, any mechanism periodically needs prophylaxis and replacement of spare parts, and for this you need to be well versed in the device of the product, in addition, repairing the chainsaw with your own hands will save time and money.
Fuel supply system repair
Fuel may not enter the cylinder for the following reasons:
- Dirty fuel filter. Remove the fuel hose and check how the fuel flows. If the jet is weak, the filter may need to be cleaned. It is taken out through the filler hole of the fuel tank and cleaned; in case of severe contamination, it is replaced with a new one. As a preventive measure, it is recommended to replace the fuel filter every three months.
- Clogged breather (holes in the fuel tank cap). Check also by disconnecting the hose, in case of blockage, clean with a needle.
- Lack or insufficient amount of fuel. There may be several reasons for the malfunction. The first reason is a clogged air filter. Air ceases to flow into the carburetor in the required amount, in this regard, due to a too rich fuel mixture, engine operation is disrupted. The contaminated filter is carefully removed, cleaned and washed in water, then dried and reinstalled.
Another reason is improper adjustment of the carburetor. Adjustment is made with three screws.
Timely replacement of the fuel filter ensures full fuel supply
The fuel hose and choke actuator must fit snugly against the fittings
The throttle lever cable must be in place
During work, you must use the instructions, otherwise you can only make it worse.
And the last reason is a violation of the integrity of the membrane or clogging of the carburetor channels.
To repair the carburetor yourself, you need to get acquainted with all its parts.
All parts must be clean, dry and in good condition.
Assessment of the state of the cylinder-piston group
Often the engine will not start or run at full capacity due to low cylinder pressure. It can be caused by piston or cylinder wear, piston ring sinking, bearing wear. You can partially examine the state of the cylinder-piston group (CPG) by removing the muffler and looking into the opened hole.
A compressor placed in the spark plug hole will help to measure the compression in the engine. according to the measurement results, you can also talk about the state of the CPG. Accurate data is obtained only after complete disassembly of the mechanism. If the piston is chipped or scratched, it must be replaced. The piston ring must be clean, free of carbon deposits, and be exactly in its place.
Piston and crank mechanism wear is considered a serious problem.
According to the results of measuring the compression, one can judge the condition of the parts of the CPG
Checking the ignition system
The first thing to do if a chainsaw breaks down is to inspect the spark plug by disconnecting the wire and carefully unscrewing it with a special key.
The components of the chainsaw ignition system: 1. flywheel with magnets, 2. ignition module, 3. spark plug, 4. high voltage wire
Unscrew the spark plug to check its condition.
Her appearance says a lot:
- Dry. Most likely, the fuel mixture does not enter the cylinder. It’s not about the ignition system, so the plug is screwed back.
- Strongly splashed with fuel. The reason for the excess fuel mixture lies either in a violation of the starting rules, or in an incorrect adjustment of the carburetor. The spark plug is carefully wiped, shut off the fuel supply and turn on the starter. to remove excess fuel and ventilate the combustion chamber. Then the candle is placed in place and the mechanism is started again.
- Covered with black carbon. This may indicate the use of low-quality oil, an incorrectly adjusted carburetor, or an incorrectly calculated gasoline to oil ratio. The candle should be washed, cleaned of carbon deposits with a sharp object (awl or needle), wipe the electrodes with a sandpaper and put in place.
When checking the candle, you need to pay attention to the gap between the electrodes: from 0.5 to 0.65 mm is considered normal. A damaged or worn gasket must be replaced.
A large amount of black carbon on the spark plug indicates a malfunction of the engine.
To be sure, you should also check for a spark. To do this, put the ignition cable on the spark plug, connect the plug nut and the cylinder with pliers, start the starter and watch for the spark. If it is missing, the plug must be replaced. If the new spark plug also does not emit sparks, the problem is in the high-voltage wire or in the broken connection with the spark plug.
Repairing the chain lubrication system
Let’s consider three main faults:
- Oil leakage. Check that the pipes are tightly connected to the pump unions and that they are not cracked. Problem tubes are sealed with sealant or replaced.
- Insufficient oil supply. Most likely, the lubrication channels are clogged.
- Cracks in the oil pump housing. Part needs to be replaced.
Here’s how to diagnose the lubrication system:
Chainsaw structural components
All chainsaws are similar in structure, regardless of whether they are European (ECHO, Stihl, Husqvarna) or domestic (Kedr, Ural). The main elements are located inside the body. the fuel tank and the engine, and outside the starter, the handle, the saw part (tire) with the chain. A sharp jerk of the cable starts the engine, and that one. the saw blade.
To begin with, we suggest that you familiarize yourself with the video clips that show how the chainsaw works and how it works:
From time to time, the saw malfunctions, which require disassembly to eliminate. What can happen to such a simple mechanism as a chainsaw? At least the following:
- Stops to start;
- Starts up, but soon stops;
- Ceases to function in the cut;
- Loses its power;
Most of the malfunctions are associated either with interruptions in the operation of the engine (fuel supply system, exhaust system, ignition, cylinder-piston part), or with malfunctions of other systems and assemblies (clutch, chain brake, tire, lubrication system). Consider the most common breakdowns and techniques for their elimination.
A serviceable chainsaw starts with one jerk and does not fail in the cut
Adjusting the chain brake
The chain brake often does not work due to clogging of grease or sawdust in the brake band and the space under the cover. All parts should be cleaned from blockages. Perhaps the tape is simply worn out, then it needs to be replaced.
The chain brake is restored by mechanical cleaning
Some parts of a chainsaw will wear out faster than others. These include the drive sprocket, tire, chain, anti-vibration elements. For quick replacement, it is best to always have spare parts on hand Chain sharpening should not be neglected.