Diagnostics and repair of the chain lubrication system
The reason for the incorrect operation of the chainsaw may be a malfunction in the chain lubrication system:
- Oil leaks, we check the tightness of the connection of the pump fitting and the tube and the presence of cracks on them, if a crack is found, the tube is changed or sealed with sealant;
- An insufficient amount of oil is supplied, it is possible that the channels supplying lubrication are clogged, which happens quite often, they should be well cleaned;
- If the oil pump housing is cracked, it should be replaced.
Engine
In most cases, the following problems are encountered in engine operation:
- The engine stops starting;
- The engine starts, but after a while it stalls;
- The engine is NOT capable of delivering the required power;
- The engine runs extremely unstable.
The chainsaw develops full power
In addition to the problem discussed above with a lack of gasoline or air entering the cylinder, the reason for the weak power may be a clogged muffler.
Chainsaw loses power under load
If in the process of work the saw power disappeared somewhere, then the problem should be looked for in the following places:
- Into the muffler. He, as you already understood, tends to clog.
- Clog the fuel filter.
- In a poorly functioning fuel pump.
Gasoline flows from the chainsaw
If gasoline drops periodically appear on the body of the chainsaw, then it is necessary to check the tightness of the fuel tank. Over time, it may dry out. Or the gasket is “hardened” and it can no longer perform its direct function.
If a full-fledged gasoline stream appears, then there is a high probability that you will have to change the burst hose connecting the carburetor and the fuel tank.
Failure of second systems
In some cases, users of chainsaws note other problems that do not significantly affect the operation of the tool.
Failure of second systems
In some cases, users of chainsaws note other problems, which do not significantly affect the operation of the tool.
Troubleshooting Algorithm
If you are sure that you can assemble the chainsaw after disassembly, then the screwdriver is in your hands. To establish the true cause of the problem, it is necessary to analyze the condition and behavior of the saw.
Chainsaw troubleshooting
Unfortunately, chainsaws, as well as other units, can fail. Having a little idea of how the saw works, you can fix most of the faults yourself. The complexity of the repair is NOT so much in the work itself, but in the correct determination of the cause of the breakdown.
For example, if the saw Won’t start, so there may be several reasons, so you should not immediately start disassembling it. First, analyze the causes of the breakdown, which are divided into 2 groups:
- Problems with engine components, ignition system, fuel supply or exhaust. This also includes malfunctions of the cylinder. piston group.
- Malfunctions in the lubrication system unit, chain brake, clutch or tire, as well as a number of other malfunctions.
Repairing the chain lubrication system
Consider three main faults:
- Oil leakage. Check if the pipes are tightly connected to the pump connection and if they are not cracked. Problem tubes are sealed or replaced.
- Insufficient oil supply. Most likely clogged grease passages.
- Cracks in the oil pump housing. Part replacement required.
Here’s how to diagnose the lubrication system:
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 of the fuel tank filler hole and cleaned; in case of severe contamination, replace 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 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 right amount, in this regard, due to a too rich fuel mixture, the engine’s operation is disrupted. The contaminated filter is carefully removed, cleaned and rinsed 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
Fuel hose and choke actuator Must fit snugly against the fitting
The throttle 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.
Checking the ignition system
The first thing to do in the event of a chainsaw breakdown 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 the violation of the starting rules, or in the improper 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, in an incorrectly adjusted carburetor or in an incorrectly calculated ratio of gasoline and oil. 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 must Pay attention to the gap between the electrodes: it is considered normal from 0.5 to 0.65 mm. A damaged or worn gasket must be replaced.
A large amount of black carbon on the spark plug indicates an engine malfunction.
To be sure, you should also check for a spark. To do this, put the ignition cable on the spark plug, pliers connect the plug nut and the cylinder, 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 conduction or in the broken connection with the spark plug.
Do-it-yourself chainsaw repair: analysis of major breakdowns and methods of their elimination
It would seem, why would a summer resident need a chainsaw, who is engaged in growing vegetables and fruits, or to the owner of a country house with 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 a chainsaw with your own hands will save time and money.
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 muffler spark arresters, clogged with combustion products.
- Remove the muffler;
- Disassemble (there are also non-separable models);
- Will clean up from carbon deposits using detergents;
- Dry with a hair dryer;
- 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 prevent clogging of the muffler, it is necessary to monitor the composition of the fuel mixture. The amount of oil should not exceed the rates recommended by the manufacturer. Poor oil quality also negatively affects engine performance.
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 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 the 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 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
Constructive components of the chainsaw
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 thes 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 starting;
- 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 second 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 is often triggered due to grease or sawdust clogging 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, bar, chain, anti-vibration elements. For quick replacement, it is best to always have spare parts on hand. Chain sharpening should NOT be neglected.
Chainsaw troubleshooting
Unfortunately, chainsaws, as well as other units, can fail. Having a little idea of how the saw works, you can fix most of the faults yourself. The complexity of the repair is NOT so much in the work itself, but in the correct determination of the cause of the breakdown.
For example, if the saw Won’t start, so there may be several reasons, so you should not immediately start disassembling it. First, analyze the causes of the breakdown, which are divided into 2 groups:
- Problems with engine components, ignition system, fuel supply or exhaust. This also includes malfunctions of the cylinder. piston group.
- Malfunctions in the lubrication system unit, chain brake, clutch or tire, as well as a number of other malfunctions.
Indicators of engine malfunction
In a malfunction of the engine, one can judge by the following arising problems:
- Impossible to start the engine;
- The engine starts, but then immediately, stalls;
- The engine is unstable;
- At idle it works normally, and under load it loses power or stalls.
All these problems can indicate a malfunction in the ignition system.
Chainsaw muffler. disassembly and cleaning
When the engine runs normally at idle and stalls when the load increases, a muffler may be a prerequisite. Spark arresters become clogged by combustion products and prevent normal exhaust. In this case, the muffler must be removed and cleaned from carbon deposits with detergents, and then dried thoroughly. While the muffler is removed, plug the hole in the engine with a clean rag. Excessive oil in the fuel mixture, poor quality or unsuitable oil for two-stroke engines can cause muffler clogging.
Troubleshooting the fuel system
Fuel cannot enter the cylinder for several reasons:
- The fuel filter is dirty. To fix the problem, remove the fuel hose and watch how the fuel will flow. In case of a weak jet, clean the fuel filter. Taking it out of the fuel filling hole, the filter is cleaned, and in case of severe contamination, it is replaced with a new one.
- Clogged breather. a small hole in the tank cap. You need to remove the hose and clear the blockage with a needle.
- The fuel has run out or is not enough. The reason is a clogged air filter. Air does NOT enter the carburetor in the required volume, the fuel mixture is too rich, which disrupts the normal operation of the engine. The filter must be carefully removed, rinsed, dried and put back in place.
- The carburetor is incorrectly adjusted. Since it is one of the main components of the engine, it is better to entrust the adjustment of the carburetor to a specialist. Self-tuning can permanently damage the engine.
We check the performance of the cylinder. piston group
Sometimes the engine does not run at full power or does not start at all due to insufficient cylinder pressure. This can be caused by wear on the cylinder, crankshaft bearings, or sinking of the piston rings due to piston wear. You can visually check the state of the CPG when removing the muffler by looking into the hole. Although the overview will be rather limited, some idea of the state of the cylinder. piston system You can get.
In order to more accurately establish the state of the CPG, a compression gauge should be installed in the spark plug hole, turned by hand with a starter or using an Electric Drill Crankshaft. The pressure of the working saw should be between 8-9 atmospheres. Lower pressure decreases engine power.
You can get a complete picture of the malfunction of the piston group cylinder if you completely disassemble the engine by disconnecting the crankcase from the cylinder and examining the piston. If there are chips or deep scratches on it, the piston should be replaced. If the cylinder surface is worn out, it is possible to bore it.
The decrease in compression may be due to wear on the piston ring. In working condition, the ring is NOT covered with carbon deposits, it is located freely in the piston groove and press firmly inside the cylinder.
Checking the ignition system
Checking the system should start with a spark plug inspection. Dry, it says that the fuel mixture has missed the cylinder and that means that the ignition has nothing to do with it. If the spark plug is too flooded with a fuel mixture, then the saw was not started correctly or the carburetor is incorrectly adjusted.
Carefully wipe the spark plug, then shut off the fuel supply, remove fuel residues, ventilate the chamber and start the starter. Then the candle is put in place and the engine is started again. Black carbon deposits indicate that you have used low-quality oil, or the percentage of oil and gasoline in the fuel mixture is violated. This may be due to an incorrectly adjusted carburetor. The candle should be washed and cleaned off the carbon with a sharp awl or needle, cleaned with a fine sandpaper of the electrodes and screwed in place.
When checking the spark plug, pay attention to the gap between its electrodes. The working limits are 0.5. 0.65 mm. If the gasket is worn or damaged in the spark plug, this can also cause problems with starting the engine. You should check the spark plug and for the presence of a spark. To do this, an ignition cable is brought to it, then clamped with pliers with insulated handles, a candle with a thread or nut is applied to the cylinder. Pulling the starter rope to check if there is a spark. If it is not there, then the candle is simply replaced. If the spark is not given by a new candle, then the problem in the high-voltage conducts.
DIY chainsaw repair
Today, almost every villager or summer resident has chainsaws. They are in high demand because they are easy enough to work with. Even in case of breakdowns, dust can be repaired by hand, although this can take a long time. On the farm, consumers use household or semi-professional (farm) saws, which are designed for a small front of work.
Diagnostics and repair of the chain lubrication system
The reason for the incorrect operation of the chainsaw may be a malfunction in the chain lubrication system:
- Oil leaks, we check the tightness of the connection of the pump fitting and the tube and the presence of cracks on them, if a crack is found, the tube is changed or sealed with sealant;
- An insufficient amount of oil is supplied, it is possible that the channels supplying lubrication are clogged, which happens quite often, they should be well cleaned;
- If the oil pump housing is cracked, it should be replaced.
Chainsaw design
Basically, all chainsaws are equipped with a two-stroke, single cylinder, air-cooled carburetor engine. The stability of operation directly depends on the carburetor, which prepares the fuel-air mixture. The air entering the engine does not have to contain dust and other impurities clogging it, otherwise the piston group will wear out quickly enough.
To avoid this, the air filter in the chainsaw should be cleaned regularly. To make it less likely to clog, it has a pre-cleaning mechanism.
The engine is started by a starter (a rope with a handle wound around the pulley). Modern, even low-power saws, Equipped with easy-to-start mechanisms. These include:
- Primer. a pump that reduces the number of empty turns, pre-pumping fuel;
- A spring starter, which allows you to slowly pull the cable, while the engine does NOT spin, but only a special spring is charged, at some point it overpowers the compression and sharply scrolls the crankshaft;
- The decompression valve connects the cylinder to the atmosphere, while reducing the pressure in it, which allows you to start the engine without much effort, the valve closes after starting under the pressure of the exhaust gases.
During operation, the chainsaw can vibrate strongly, therefore it is equipped with an anti-vibration vibration damping system. The saw handles are connected to the motor by means of a damper (rubber gasket or steel spring).
The sawing part of the chain consists of a cutting chain located at the edges of the bar, a sprocket and a sprocket.