DIY chainsaw repair: analysis of the main breakdowns and methods for their elimination
It would seem, why a chainsaw to a summer resident, who is engaged in the cultivation of vegetables and fruits, or to the owner of a country house, which has a small garden and several flower beds? The question disappears when there is a desire to build a bathhouse, renovate a greenhouse, tumble down an old business, or just make a bench for relaxation. Unfortunately, any mechanism periodically needs to be prevented and parts replaced, and for this you need to understand the device’s structure well, besides, repairing a chainsaw with your own hands will save time and money.
Structural components of chainsaws
All chainsaws are similar in structure, regardless of whether they are European-made (ECHO, Stihl, Husqvarna) or domestic (Cedar, Ural). The main elements are located inside the case - a fuel tank and an engine, and outside the starter, handle, saw part (tire) with a chain. A sharp jerk of the cable starts the engine, and that - the saw blade.
To get started, we suggest you familiarize yourself with the video clips that show how the chainsaw is arranged and how it works:
From time to time, malfunctions occur in the operation of the saw, the removal of which requires disassembly. What can happen with such a simple mechanism as a chainsaw? At least the following:
- Ceases to start;
- Starts up, but soon stops;
- It ceases to function in the cut;
- Loses its power;
Most of the problems are associated with interruptions in the engine (fuel supply system, exhaust system, ignition, cylinder-piston part), or with malfunctions of other systems and components (clutch, chain brake, tire, lubrication system). Consider the most common breakdowns and methods for eliminating them.
A working chainsaw starts up with one jerk and does not fail to cut
Ignition System Check
The first thing to do when a chainsaw breaks down is to inspect the spark plug by disconnecting the wire and carefully twisting it with a special key.
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 get into the cylinder. It's not about the ignition system, so the candle is twisted back.
- Heavily splattered with fuel. The reason for the excess fuel mixture lies either in violation of the start rules, or in the incorrect carburetor adjustment. The candle is carefully wiped, the fuel supply is shut off and the starter is turned on - to remove excess fuel and ventilate the combustion chamber. Then the candle is put in place and the mechanism is started again.
- It was covered with black soot. This may indicate the use of low-quality oil, an incorrectly adjusted carburetor or an incorrectly calculated ratio of gasoline to oil. The candle should be washed, cleaned of carbon deposits with a sharp object (with an awl or a needle), wipe the electrodes with a skin 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. Damaged or worn gaskets must be replaced.
A large amount of black soot on the spark plug indicates engine malfunctions
For complete certainty, the presence of a spark should also be checked. To do this, put the ignition cable on the spark plug, connect the spark plug nut and cylinder with pliers, start the starter and watch for the appearance of a spark. If it is absent - the candle needs to be replaced. If the new candle also does not give out sparks - the problem is in the high-voltage wire or in the failure to connect to the candle.
Fuel system repair
Fuel may not enter the cylinder for the following reasons:
- Fuel filter contamination. Remove the fuel hose and check for fuel leaks. If the jet is weak, you may need to clean the filter. 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). Also check 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 clogged air filter. The air ceases to flow into the carburetor in the right amount, in this regard, due to too rich fuel mixture, the engine is disrupted. The contaminated filter is carefully removed, cleaned and washed in water, then dried and replaced.
Another reason is the incorrect carb adjustment. Adjustment is made by three screws.
Timely replacement of the fuel filter ensures full fuel supply
The fuel hose and choke drive must fit snugly against the fittings.
The throttle control lever cable must be in place
During operation, you must use the instructions, otherwise you can only make it worse.
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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 details
All parts must be clean, dry and intact.
Dismantling and cleaning the silencer
If the engine works fine at low revs and starts to stall at high revs, the cause may be covered in a silencer spark arrestor clogged with combustion products.
- remove the muffler;
- disassemble (there are non-separable models);
- clean off deposits using detergents;
- blow dry;
- set in place.
Dry cleaning is unacceptable, as there are carcinogens in the tan, inhalation of which is hazardous to health. After removing the muffler, the outlet is closed with a clean rag.
Chainsaw malfunctions indicate possible muffler clogging
To prevent clogging of the muffler, it is necessary to monitor the composition of the fuel mixture. The amount of oil must not exceed the norms recommended by the manufacturer. Poor oil quality also negatively affects engine performance.
Assessment of the condition of the cylinder-piston group
Often the engine does not start or does not work at full strength due to the low pressure in the cylinder. It can be caused by wear of the piston or cylinder, dropping of the piston rings, wear of the bearings. Partially consider the state of the cylinder-piston group (CPG) is possible by removing the muffler and looking into the opening.
A compressometer placed in the candle hole will help to measure the compression in the engine - according to the results of the measurement, you can also talk about the state of the CPG. Accurate data is obtained only after the complete disassembly of the mechanism. If the piston has chips or scratches, it must be replaced. The piston ring must be clean, without carbon deposits, and be exactly in place.
Wear on the piston and crank mechanism is a serious problem.
According to the results of measuring compression, you can judge the condition of the parts of the CPG
Repair chain lubrication system
Let's consider three main faults:
- Oil leakage. Check whether the pipes are tightly connected to the pump fittings and if there are any cracks on them. Problem tubes are sealed or replaced.
- Inadequate oil intake. Most likely, the lubrication channels are clogged.
- Cracks in the oil pump housing. Part replacement required.
Also, material on how to sharpen a chain of a chainsaw will be useful: tech / kak-zatochit-cep-benzopily.html
Here's how to diagnose a lubrication system:
Chain brake adjustment
The chain brake often does not work due to clogged grease or sawdust brake tape and the space under the cover. All parts should be cleaned of blockages. Perhaps the tape has simply worn out, then it needs to be replaced.
The chain brake is restored by mechanical cleaning.
Some parts of the chainsaw 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 at hand. Do not neglect the sharpening of the chain.