Why does the chainsaw stop when you throttle it?
If the chainsaw does not start and stops, the performance of the simplest sawing jobs is out of the question. Not only budget-priced tools are prone to spontaneous failures, but also quite prestigious models from leading manufacturers.
The cause of a chain saw stopping in the middle of work can be:
- Poor quality of components and whole assemblies;
- unskilled care;
- the use of low-quality fuel and oil surrogates;
- illiterate operation.
Remoteness from service stations and the high cost of repair services provided, forcing owners of failed tools to restore their performance on their own.
Such a situation is only possible after the warranty period has expired. The difficulty lies in the fact that noticed by service technicians traces of dismantling individual assemblies and units can be the reason for refusing free repair of more complex and expensive parts.
The advantages of do-it-yourself repair
Specialists offer several ways to find the cause of a poor engine start or if the power unit shuts down during operation. Recommendations are equally valid for chainsaws of domestic and professional class.
Owners with chain saw experience use simple, time-tested, intuitive troubleshooting algorithms that allow them to quickly fix many failures and malfunctions right in the process.
Knowledge of the tool design and the interaction of all its components, as well as familiarity with locksmith and repair skills and operating experience, contribute to the success of the work. These same skills allow owners to operate their chainsaw more effectively.
Self-repair provides an opportunity to save considerable material resources and reduce the time of forced outages.
Determining the nature of the fault
Most chain saw failures in any class are in the fuel system. For the ignition system, this is an order of magnitude less. A chain saw stopping due to mechanical faults is even rarer in the practice of domestic and professional sawing work.
Electrical equipment
Faults in the ignition system are determined quite simply by checking the spark plug and adjusting the gap in the contacts. After checking the integrity of the wiring, the causes of failure should be sought in the work of the electronic unit.
Lack of spark on the contacts may be due to breakdown of the interference resistor located in the body of the spark plug. To check its integrity it is enough to connect the high-voltage wire directly to the spark plug.
Mechanical failure
Sudden stopping of the chainsaw can be caused by jamming of the piston in the cylinder or destruction of the crankshaft bearing due to oil starvation or poor quality of engine oil.
In the first case operability of the tool can be restored by pouring a few drops of engine oil into the spark plug hole. Damage to the crank mechanism can be repaired with a complete disassembly in a well-equipped workshop.
Elimination of fuel equipment failures
A simple analysis of failures and malfunctions shows that most of them are caused by unqualified adjustment of the fuel system. A closer look reveals that the causes of the situation when the engine does not start, does not pick up speed and stops are practically the same.
In the majority of cases these are:
- air intake due to loose screw fasteners or crankshaft gland packing failure;
- contamination of the nozzles;
- leakage of the float valve;
- Wear of the booster pump seal.
Signs of typical failures
If the engine does not rev up and shuts down, has no power and shuts down under load, it is probably a fuel shortage or a faulty carburetor adjustment.
The list of possible causes includes a dirty fuel filter or air intake filter element, too rich or poor gasoline-air mixture.
Signs of an engine running on a rich mixture:
The chainsaw stalls when you step on the gas. most likely the mixture is too lean.
A simple way to determine mixture quality
The easiest and most accessible way to check mixture quality is by the center insulator of the spark plug. Brown color of any intensity indicates that the carburetor is properly adjusted.
Working with a rich mixture results in the formation of black carbon deposits on the insulator, a poor mixture results in a clean insulator of white or light gray color.
If, after a normal warm-up, the fuel-fuelled cut-off saw cuts out intermittently during operation, it is advisable to clean the breather plug to eliminate the vacuum in the fuel tank. The reason of unstable engine performance may be caused by condensed water in the carburetor float chamber.
Engine shut down on operating mode
In another version, if the chainsaw heats up and shuts down, the fault should be sought in the settings of the carburetor or in the high voltage circuit of the ignition unit.
the spark disappears or becomes so weak that its power is insufficient to ignite the air-fuel mixture.
The engine also stops on hot when the interference resistor, which is located in the tip of the spark plug, is defective.
Engine stalls when switching to idle mode
The malfunction is manifested by unstable operation in the operating mode and throttles at idle speed. The cause of this phenomenon is most likely a leaking air between the carburetor and the cylinder intake. The failure can be eliminated by tightening the screw fasteners.
The chainsaw engine shuts down after reaching maximum rpm
High revs and engine power cuts out because the electronic block does not perform as advertised. The problem is more common with low-priced chain saws made in China.
Chainsaw stalls when pressing the gas: the cause, how to eliminate when pressing the gas, Husqvarna-137 at idle speed, does not start under load
It is not uncommon for owners of chainsaws to face breakdowns, and it does not matter what model of this kind of equipment, because the nature of the breakdowns is almost the same for all. Well, here’s a chainsaw stalled and what next? Undoubtedly, you can take the technique to a specialized service, which for a fee will repair your “iron friend”. But as they say: why pay more??
After all, you can disassemble the tool and repair it yourself, as the breakage may be insignificant, but at the service you will pay a lot. But of course in order to bring the tool back to life on your own you need to be able to understand the causes of its failure and troubleshooting methods. So let’s learn! In this article you can find answers to questions about situations, when the tool simply stops after you directly press the gas. So, here we go.
The basic elements of chainsaws
Before we get into the issues of tool repair and malfunctioning, let’s first understand what a chainsaw actually consists of. First of all, I would like to note that this tool belongs to the category of equipment, the work of which depends directly on the internal combustion engine.
It is also important that chainsaws are equipped with an engine that has one cylinder, and the work of which is carried out on this kind of fuel, such as gasoline. It’s worth noting that, despite its similarity to other tools, it has no gearbox. It is replaced by a kind of single chain gear, through which the movement of the chain itself (saw) is made.
In essence, the chainsaw is a fairly simple design, but this does not prevent it from being reliable, practical and able to fully provide direct uninterrupted and cyclic work even in quite difficult conditions. This tool consists of a huge spectra of certain elements “vital” for its proper and productive operation. This includes the carburetor, the direct chain tensioner, the bar complete with chain, and other.
Before you buy a chain saw, be sure to research all of the options and choose the brand of chain saw that is right for you.
To help you choose, we’ve put together a reliability rating for chain saws.
If you are on a tight budget, read the article about Russian chainsaw makers.
Why does the chainsaw quit and choke when you step on the gas?
Chainsaws are fairly rugged and uncomplicated designs. That’s why if you take proper care of them and treat them according to the manufacturer’s recommendations then they break down very seldom and all kinds of failures are eliminated fast enough. But if you are faced with this situation and you want to repair your tool yourself without the help of professionals, then read the information below.
As a matter of fact, it is impossible to exactly and unambiguously define the reason why the tool doesn’t start or stops when you press the gas button, as there are many factors that influence this. But let’s not forget the fact that a chainsaw is equipped with a simple two-cycle engine, and the following conditions are important for its effective performance: lubrication, fuel, spark and air.
So, while the air-fuel mixture is prepared by the carburetor, the filter cleans dust from the air and the spark plug creates the spark and the lubricant in the gasoline.
That is why it is necessary to search for the causes of this kind of failure in a sequential order, starting directly from the simple and gradually moving to the complex. This is an important factor in the correct repair, because the person who begins to engage in disassembly of the carburetor without thinking, leads her to the risk of. Because this kind of unit should be repaired or adjusted directly in special workshops (read about carburetor adjustment).
Improper fuel
It is important to remember that in order for a tool to operate without failures, it is necessary to pay attention to the fuel itself. Because if this kind of mixture will not be prepared correctly, most chainsaws simply will not start. Consequently, not every chain saw owner would think to look for the reason in the fuel. That is why in order for your tool to work properly you need to use only high quality gasoline.
To use only oil that is made by your tool manufacturer. In addition it is important to prepare this kind of mixture in the exact quantity that you will use in one or two weeks, but no more (see Section 5.2.1). the ratio of petrol and oil for a chainsaw).
Otherwise overcooking the mixture directly in the canister will lead to the fact that it will lose all its octane properties and it will lead to significant problems with the tool.
Mixture pouring into the spark plug while the machine is running
Just as the cause of failure can be a direct pouring of the mixture at the moment when the mechanism is running. In order to solve this problem it is necessary to unscrew and dry the spark plug, but remember that it must not be calcined in any way. Excess fuel must be drained through the hole (spark plug), wait 20-30 minutes, then install it in place and try to start the tool again.
There is no spark and the chainsaw will not pick up
A chain saw stops when you press the gas because there is no spark. This can happen when there is no good contact between the spark plug lug and the (high-voltage) wire. However, if this kind of connection works correctly, but there is still no spark, then the ignition unit (electronic) is the cause. It is important to note that these kinds of parts are not repairable, so they can only be replaced.
Do not forget that by inspecting the spark plug you will be able to obtain significant information regarding the breakdown of the chainsaw. Since if its surface is dry, it is caused by a cylinder that is not fed directly with fuel. That’s why you’ll have to check the entire range of its supply step by step. If the candle is all black soot, it means that the carburetor is not working properly, that is, it either supplies a lot of fuel, or overflows oil directly into the gasoline.
Characteristics of a chainsaw internal combustion engine
The main chainsaw malfunctions are related to engine failures. As the chain drive domestic and foreign manufacturers use single-cylinder two-stroke internal combustion engines. The design of the engine is simple. Ignition is ordinary, without the installation of capricious electronics. Chainsaw engines can operate reliably in various climates. Fuel for a carburetor engine is derived by mixing AI-92 gasoline and specialty oil. Since there is no oil pump in the design, the piston and cylinder are lubricated with a mixture of gasoline and oil. The chainsaw engine develops power from 2 to 5 kW and the crankshaft speed goes up to 14000 rpm. Such high RPM and loads place very high demands on the oil. Use oil specified in manual. When oil is changed to normal engine oil, tool life is drastically shortened. Remember that filling the tank with gasoline without adding oil is strictly forbidden.
Why doesn’t the chainsaw chain turn when the engine is running even at full speed??
- Drive sprocket. Either it is jammed, or the ring gear is so worn that it does not mesh and the chain does not turn on the chainsaw. In either case, the sprocket will need to be disassembled to find out the exact reason why the chain does not turn. If the sprocket is worn, the sprocket must be replaced (or the sprocket itself if the sprocket is of a fabricated design).
- Chain brake stuck. This will cause the sprocket to lock in the brake mechanism and keep the motor running. You must turn off the engine and release the brake. If it is under load, the brake mechanism will need to be replaced as well as the sprocket.к. Many parts can melt and overheat because of the high temperatures.
Tools and supplies
Two-stroke chainsaw engine diagram.
The chainsaw’s mechanical components are well built and repairable. Nearly all components and parts are easily accessible. With the right tools, they are easy to remove for repair or replacement. To conduct disassembly and check the life-support systems of the chainsaw engine, you should stock up with such tools and materials:
- a set of locksmith and installation tools;
- socket wrench;
- tester;
- pressure gauge to measure compression;
- feeler gauges to measure gaps;
- needle;
- sandpaper;
- fuel mixture (gasoline oil);
- rags.
Why the chain saw does not start or stops. causes and ways to fix
A chainsaw is a household tool, which, during its operation, succumbs to an intensive load. Over time, many of the saw’s parts and mechanisms cannot withstand the increased wear and tear and fail. The first sign of a serious breakdown of a garden tool is already evident when its engine won’t start. In this case, the first thing that the operator must do. is to find the cause of the breakdown and quickly eliminate it.
Each time properly starting the engine of the household gasoline chainsaw, its owner ensures smooth and smooth operation of the mechanisms of the garden tool, as well as prevents rapid wear and tear of its consumables. The procedure for starting a cold engine of different models may vary slightly, but in most cases it looks as follows:
- The first step that the operator must always take is to set the lever adjusting the position of the integrated throttle flap to its lowest position. Please note that this will only move the lever into this position if the throttle trigger is pressed. By moving the lever down the operator closes the choke located in the standard carburetor and locks the throttle lever in the clamped position;
- Next you need to start manipulating the starter rope. To do this you need to put your right foot in the “ear” located in the back of the housing, and rest your left hand on the chainsaw handle. Then you should sharply pull the cable of the integrated starter of the garden tool several times. As soon as the saw engine starts and stalls, the throttle position lever will need to be moved up one position;
- After that you need to pull the pull cord of the pull starter again several times. The engine should now start and immediately reach its maximum rpm. This is due to the fact that the operator has previously locked the throttle trigger in the clamped position;
- Then pull the throttle trigger once and immediately release it. The throttle trigger should now be in its operating position. At the same time, the engine speed will decrease. This means you can now start to use the chain saw on the site.
If the operator needs to start the gardening tool with a warm engine, this is done by moving the throttle valve lever to the penultimate up position and pulling the starter rope. To turn the engine off, the throttle position switch lever must be moved to the extreme up position.
In some models of chainsaws used in the household, starting the factory engine is done in this sequence:
- First you need to turn on the ignition and move the toggle switch to the appropriate operating position;
- Next you need to press the transparent plastic primer, required for pumping fuel into the cylinder 5-6 times;
- The operator will then be required to fully pull out the throttle in-line throttle position adjustment lever;
- Then pull the recoil starter rope sharply several times. As soon as the factory engine starts and stalls, the throttle control lever needs to be pushed all the way in and the starter lever needs to be pulled a few more times. The instruction manual of some models specifies that after the engine stops, the choke adjustment lever should be pressed only halfway. In this case it is necessary to press the lever to the end only after the start and the beginning of stable work of the engine of the chainsaw;
- In models where the throttle trigger is locked when the throttle control lever is pulled, the engine will start to run at high RPMs. If the gas trigger in the chainsaw is not fixed, then the engine speed will be minimal. Because of this, the internal combustion engine, a few seconds after starting, may stall. In this case it is necessary to start the engine of the garden tool until it warms up and starts working more stably.
If the operator has to start the chainsaw with a warm motor, he will only have to turn on the ignition and pull the starter rope sharply a few times.
Why the chainsaw does not start. causes and remedies
Over time, the working mechanisms of the garden tool wear out, resulting in various malfunctions of the chainsaw. To eliminate them with their own hands, the operator must quickly determine the cause of the breakdown and replace the faulty part.
What to do if the chainsaw stalls when you press the gas?
If a chainsaw used on the farm or in logging operations runs normally at idle, but shuts down under load, this, in most cases, can indicate two common malfunctions. The first common cause is a clogged air or fuel filter. To inspect the parts you need to remove the plastic cover on the body of the saw. It will help to clean the filter elements by rinsing them thoroughly in clean gasoline. If it was not possible to clean the filters, then they need to be replaced.
It is not uncommon for a chainsaw to warm up and shut down because of a faulty fuel pump. It works under the influence of the gears, which, during intensive work, wear out quickly. It may help to replace the defective gears or the entire pump.
In order to avoid similar problems in the future, you need to be careful in choosing the components of the fuel mixture to refuel the chainsaw. Only use gasoline with the octane rating specified by the manufacturer of the garden tool. When selecting engine oil, the saw operator should give preference to products from brands that produce oils with all the additives necessary for stable tool operation.
The chainsaw starts normally, but stalls when you add gas. repair the problem
The main reason for this malfunction should be looked for in the initially incorrectly adjusted carburetor by the operator. If the tool picks up revolutions and stops, then, most likely, due to a mechanical shock or increased vibration, the factory settings of the adjusting screws of the fuel unit have been violated. To solve a common problem that causes a used tool to quit on heat, the carburetor needs to be adjusted.
If after adjusting the carburettor the garden tool keeps stopping on loading then the fuel pipes should be checked carefully. If a hole is formed in one of them, the fuel will not be able to fully enter the internal combustion engine cylinder. Because of this, the garden tool will randomly shut down during the revs.
Often the chainsaw will stall when you throttle it, because the air filter is not working properly. To solve the problem of arbitrary engine shutdown on hot, it is enough to wash the element and the space under it with clean gasoline. The filter should then be installed and the operation of the garden tool carefully checked again.
Chainsaw starts and shuts down. causes of failure
This is a common problem encountered by users who partially use their chainsaws in hard-to-reach places. In these conditions, the saw inevitably suffers mechanical shocks, resulting in a gap between the ignition coil and the magneto.
For a stable ignition system, the clearance between the magneto and coil of the chainsaw must not exceed 0.5 mm. In some models of professional chain saws, this parameter can be 1-2 mm more.
To properly adjust the gap between the parts of the ignition system, it is necessary to remove the left side protective cover of the housing. Then you need to unscrew the 2 screws located by the factory next to the flywheel. Once the flywheel is away from the coil, you will need to attach a special template to the latter, which has a thickness corresponding to the gap between the built-in flywheel and coil. After that you need to turn the screws clockwise in turn, thus bringing the handwheel closer to the template.
If this did not help, then it is necessary to check the condition of the gas cylinder engine of the chainsaw. As a result of prolonged work on the inner walls of the cylinder are formed burrs or other defects that interfere with the normal operation of the motor. In this case, it will be necessary to carefully grind the damaged surface of the cylinder and try to start the chainsaw again.
There is a spark, the spark plug is wet. the solution to the problem
The main cause of this malfunction is the use of a low-quality fuel mixture, prepared in the wrong proportion. Because of the overabundance of engine oil, it eventually overflows into the cylinder and gets on the spark plug. At first the spark plug may still produce a spark, but over time, this ability is lost.
The first thing to do to fix the problem is to unscrew and flush out the soot from the spark plug. If the resin on the surface of the component has time to solidify, you can use a lighter that will heat and melt the soot. In this case, be very careful not to damage the spark plug pins. Next you need to wash the part in clean gasoline and dry it thoroughly.
While the spark plug is drying, the operator must dry the saw’s cylinder. To do this, pull the starter rope several times. Then the spark plug should be installed and an attempt should be made to start the chain saw engine.
often than not the cause of a glow plug is a damaged or depressurized fuel tube. If one of the hoses was damaged exactly in that place, which is located close to the spark plug, it is likely to be the cause of pouring the part. To correct the problem, replace the fuel tube. You will need to thoroughly clean the connections to the fittings with a moisture-resistant sealant.
The saw shuts off when you turn it
In a horizontal position the fuel tube is at the bottom of the tank, but if you tilt the tool, the fuel will not be able to cover it completely. This is the reason why the chainsaw stops working when tilted, because the tube is levitating in the air and the right amount of mixture is not getting to it.
If you notice that the chainsaw has no problem starting up without warming up, and after warming up it shuts down. And it will not start until it cools down, then there may be several problems.
First, there may be a hose, gland or gasket leak somewhere. Second, inspect the muffler for fouling. The third cause is in the cylinder-piston group (CPG), there are no scrapes or irregularities there.
Sometimes you need to adjust the carburetor. Another important cause of malfunction, is the ignition coil. In cases when it malfunctions the spark is lost or becomes very weak, which is not enough for ignition of the fuel mixture.
The master has been known to try the engine hard, then on cold, then on hot, thereby pumping the fuel. Here you need to pull yourself together, turn the choke to “hot start” and gradually start the tool. In this case, knock down the speed to almost idle and 40-45 seconds it warms up.
The saw stalls after releasing the “gas
Here you need to adjust the carburetor and check whether there is no strong air suction.
The most common cases of chain saw breaks we have already discerned. You can only hope that your saw has a long and trouble-free life. But even sturdy models like STIHL and Partner can sometimes go wrong.
Do not rush immediately run to the service center, first use my advice, so you can avoid large monetary costs.
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