Stihl 180 Replacement Crankshaft Bearings
With all the desire, a chainsaw can not be attributed to complex devices. Over, the simplicity of the design is its hallmark. But repairing a chainsaw, however, can be time consuming. The difficulty is not directly in repairing the chainsaw with your own hands, but in accurately diagnosing the malfunction. One sign of inoperability can be caused by many reasons. Therefore, before disassembling the engine or carburetor, it is necessary to analyze the symptoms of the malfunction well. In-house repair instructions for chainsaws do not replace simple logic.
Types of chainsaws
A chainsaw is a tool that cuts wood with a closed chain and is equipped with a two-stroke gasoline internal combustion engine. The capabilities of the chainsaw to work continuously for a certain time are the main distinguishing ability, which should be paid attention to.
The main units of the chainsaw design are: a chainsaw tire, a chain and a gasoline engine that drives the chain and tire. By scope and functionality, chainsaws are divided into the following categories: professional, semi-professional and domestic amateur.
Amateur chainsaws are used mainly in everyday life, for gardening in the countryside or at the cottage. Such saws are very light in weight (3-4 kilograms without chain and tire), compared with their older brothers, their vibration is very low, which makes working with this device quite comfortable. Household chainsaws are primarily designed for a short period of use (about 5 hours per week), the motor power is small, but these shortcomings are compensated by the ease of operation. With the help of household chainsaws, most often summer residents do a little work. Harvesting, firewood, cutting garden trees and pruning branches.
With a semi-professional chainsaw, you can easily perform a wider front of work. From repairs on its site to lumbering. The continuous operation of such a saw is 2-3 hours a day. The power of the gasoline engine in semi-professional devices is increased. You can achieve maximum performance, to block trees with medium and small trunk diameters. Semi-professional chainsaws are often used for cutting knots. The only difference between such devices from professional ones is that they cannot be used continuously throughout the entire working day.
Professional chainsaws are mainly used in logging and in industry. The engine power of professional chainsaws is designed for sawing trees of any size and diameter. Such chainsaws are made of wear-resistant material and have a particularly strong chain, which allows you to work continuously for 8-16 hours.
Chainsaw malfunctions
All chainsaw breakdowns are conventionally divided into two groups: engine malfunctions with all its systems and components (fuel supply system, ignition, exhaust system, cylinder-piston group) and malfunctions of other components (lubrication system, clutch, tire, chain brake).
Violations in the functioning of chainsaw engines occur quite often, it is their correction and detection that takes the most time from users. They are reduced mainly to such manifestations: the engine does not start, the engine starts, but stalls or does not work at all, the engine does not develop power, that is, it works normally at idle, but stalls under load.
When repairing a Stihl chainsaw with your own hands, it is necessary to proceed by the method of exclusion. Check alternately all possible causes of failure, starting with those that will take you less time to diagnose and fix.
Ignition system
Almost all types of engine malfunctions that were listed above can be caused by malfunctions of the ignition system. If they occur, troubleshooting is recommended to start with a candle. This is justified by the fact that its condition will also provide useful information about the functioning of the fuel system. If a problem occurs, turn out the candle and inspect it.
When the candle is dry, then most likely the problem is not in the ignition system, but in not getting the fuel mixture into the cylinder. You can wrap the candle back and take on the fuel system. When a candle is sprayed with a fuel mixture, there is an overabundance of it. This can be triggered by the misregistration of the carburetor or a violation of the rules for starting. The candle needs to be wiped and dried, draining the cylinder, then. Shut off the fuel supply and run with a starter to remove excess fuel. After that, reinstall the candle and restart the launch.
Maybe, in your case, the ratio between gasoline and oil in the mixture, the carburetor, is violated. Not adjusted or poor quality oil is used. Wash the candle in gasoline, clean the soot with a needle or an awl, clean the electrodes with a fine sandpaper and replace it. Even when repairing a Goodluck chainsaw with your own hands, which consists in checking the spark plug, there is great reason to believe that the faults are in the fuel system, you need to check the spark plug for a spark.
If there is no spark, simply replace the candle. The reasons for the absence of a spark can also be hidden in a failed ignition module or in violation of the gap between the flywheel magnetic circuit and it. The distance should be 0.2 millimeters. Violation of the gap becomes especially likely if before that you disassembled the saw with the removal of the ignition module and the flywheel. The clearance must be set using a gasket, which has a thickness of 0.2 mm, placed between the ignition module and the flywheel boss. A defective ignition module must be replaced.
Stihl 180 Replacement Crankshaft Bearings
Fuel supply system
If it was established by inspection of the spark plug that no fuel is entering the cylinder, it is necessary to consider all the reasons for this. In particular: not getting fuel from the tank due to the hole clogging in its lid; in this case, a vacuum is created in the tank, which prevents fuel from flowing out; insufficient intake or non-entry of fuel from the carburetor into the cylinder; contamination of the fuel filter that is installed in the tank.
The insufficient supply of fuel or the lack of the correct ratio between air and fuel, which are mixed in the carburetor, occurs for the following reasons: due to an unregulated carburetor, clogging of the air filter, clogging of the mesh filter or carburetor channels.
Chainsaw repair, as a rule, is not complete without cleaning the air filter, as it gets dirty quite quickly. When this happens, air entering the carburetor is reduced, at the outlet the fuel mixture is too enriched, and this in turn disrupts the normal functioning of the engine. A dirty filter must be removed for cleaning very carefully so that dirt does not enter the carburetor. Clean the filter or rinse in water with detergent, dry and reinstall.
Eliminate the misregistration of the carburetor by adjusting it. This can be done with three screws. Minimum and maximum speed. Carry out the adjustment in strict accordance with the instructions for repairing the chainsaw, failure to observe which often leads to engine damage. Some manufacturers of chainsaws leave one adjusting screw to prevent unwanted interference by inexperienced users in the operation of the carburetor.
If carburetor adjustment does not help, it is recommended to clean the filter mesh and channels, as well as check the membrane for integrity. The carburetor is one of the most complicated chainsaw devices, therefore, it is necessary to start disassembling and cleaning it with an understanding of the responsibility of this operation. This unit consists of a large number of small parts that have the unpleasant feature of jumping out of their place unnoticed and lost forever, so that after disassembling this capricious device, it may not be possible to assemble it.
Muffler
The cause of the engine malfunction, especially if it functions normally at low speeds and stalls under loads, is the clogging of the muffler spark arrester by combustion products, which interferes with normal exhaust. In this case, repairing a Husqvarna chainsaw with your own hands consists in removing the muffler, if it is collapsible, then. In disassembly, and wet cleaning of the unit from soot using detergent.
After washing, dry the non-separable muffler with a hairdryer. Remember that tanning contains substances that are carcinogenic, and dry cleaning, after which they can be inhaled, is unacceptable. When removing the muffler, plug the engine outlet with a clean rag.
The silencer can become clogged for the following reasons: due to the use of a fuel mixture with a large amount of oil (oil level is recommended by manufacturers), the use of low-quality oil or oil, which is not intended for two-stroke engines.
Cylinder piston group
The most serious are the breakdowns of the cylinder-piston group of the chainsaw. This is the deterioration of the piston and cylinder, seizures and scratches on their surface, dropping in the grooves of the piston ring and their wear, as well as the wear of the crankshaft bearings. In the usual manner, these malfunctions provoke a drop in the pressure level in the cylinder and the inability to start the engine in the future, or its inability to give full power.
There are several methods that help to assess the condition of the cylinder-piston group. Remove the silencer and look through the window where a part of the side surface of the unit is visible. Despite a limited overview, you can get a general idea of the CPG.Turn the crankshaft manually using an electric motor with a flexible shaft or a starter, while controlling the pressure on the manometer.
For a workable chainsaw, the latter should be in the range of 0.8-0.9 MPa. With its fall, the power of the engine decreases. At a pressure level of 5 atm, the engine can and will work, but at idle.
It is possible to assess the exact state of the CPG only after repairing the sawless saw stall with their own hands, which consists in disassembling the engine. Disconnecting the crankcase from the cylinder and removing the piston. If there are scuffs, deep scratches or chips on the last, it must be changed. In case of damage to the surface of the cylinder or working out, there is a chance to squander it under the repair size. The causes of low compression are coking and wear of the piston ring. Serviceable rings are always clean of carbon deposits, sit freely in the piston groove and press firmly against its inner surface.
Chain lubrication
Rare Ural chainsaw repair manuals do it yourself without mentioning breakdowns of the chain lubrication system, which are quite common. Usually they are manifested in insufficient supply or non-receipt of lubricant on the chain and in the formation of smudges of oil. If the chain. Dry, first of all, it is necessary to inspect the channels through which oil is supplied to the tire and clean them. Their clogging is not a rare occurrence.
In case of significant oil leakage (a small level of leakage is considered normal), it is recommended to check the tightness of the connection to the pipe pump fittings. They may crack or fall. In addition to smudges, a violation of the tightness of the oil line can provoke insufficient chain lubrication. The pump will suck in air, which will necessarily affect its performance. It is customary to eliminate such violations by sealing tubes or replacing them. The most serious malfunction of the lubrication system are cracks that form in the body of the oil pump. It must be replaced in this case.
Natural wear
Some parts of the chainsaw that are subject to normal wear and tear should be replaced after a useful life. Their failure is a regularity and not at all a malfunction. Wear parts include a tire, a chain, a drive sprocket, anti-vibration system units and others.
If you do not repair the husqvarna chainsaw in time with your own hands and replace the wearing parts, then excessive wear will affect the other parts of the chainsaw in the most negative way. In particular, if you do not change the drive sprocket and tire in time, then increased vibration will adversely affect the crankshaft bearings. The limit of the depth of the teeth of the sprocket should reach 0.5 millimeters.
Although the stars in practice often operate up to 1 millimeter or more to wear, not suspecting that this causes an increase in the loads on the crankshaft bearings, their accelerated failure. When three or four chains have worn out, you need to change the tire directly, if its wear by this time reaches the limit value.
The chainsaw tire wears out especially in areas whose cutting occurs most frequently, usually on the underside of the guide bar. When changing the chain for uniform wear, the tire must be turned 180 degrees relative to the horizontal axis.
Now you know that you can fix the malfunction in the chainsaw with your own hands. To do this, you should always have at hand an instruction manual for repairing chainsaws. And in order to finally understand this difficult matter, we suggest you watch a about repairing a chainsaw, which will help to consolidate all the acquired knowledge in practice.