Why The Petrol Mower Won’T Start

The petrol cutter does not start, or starts, but stalls. What is the reason?

The petrol cutter will not start, the spark is gone

The loss of a spark entails checking the contacts and the correctness of the gap between them, the conducting wires to the candle and the candle itself.
The way to check the spark is to unscrew the candle, connect a wire to it, put the candle sideways to the engine casing and pull the starter several times as if starting a petrol cutter, while looking at the coal and the contact of the candle, a spark should run between them.
If there is no spark, take a new candle, follow the same procedure, if the spark cannot be traced, then there is a problem in the wire or contacts, it is better to replace them.

The benzokos starts up and stalls. What to do?

1. There is a spark, and everything seems to be normal, but the petrol cutter will not start, in such cases, you should check the air access valve to the fuel tank. A clogged valve leads to the creation of a vacuum in the tank, in which the carburetor does not receive enough gasoline, so the petrol brush will start, but then stall. To exclude this reason, you need to clean the valve and try to start a petrol cutter with a tank cap that is not completely twisted.
2. If the brushcutter does not start at the same time, you should remove and clean the fuel filter, as well as check all the carburetor parts, and then try to start. The petrol cutter will not start again, the air filter is disconnected, try to start without it, if the mower starts up, the reason is in the air filter, replace it.

The benzokos does not start on a cold

When starting a cold engine, it is not recommended to press the gas. Tilting the brushcutter so that the air filter is on top, press the fuel suction button 5-6 times, set the function switch lever to the start position, pull the starter cord several times until the engine starts. After a few seconds of running the motor, turn off the starting system.

The gasoline cutter won’t start after winter

In such cases, the unit must be serviced. Remove the fuel system, including filters (air, fuel), disassemble the carburetor, clean and rinse each unit. Blow out the filters with air. Pay attention to fuel quality and octane number.

It should be borne in mind that products of such well-known companies as STIHL, Husgvarna and other brands will not run on cheap gasoline with a low octane number.
Suitable fuel for them is from the AI ​​92 brand and above from car refueling stations and then from well-recommended ones, since there is also bad gasoline at refueling stations. The use of high-octane and high-quality gasoline will determine how long the brushcutter will be used and how long it will last.

It is necessary to take into account one more fact that with a long storage of a diluted fuel mixture, its working qualities fall, which also leads to consequences in which the petrol cutter will not start. Therefore, it should be diluted in portions, that is, the amount of the mixture that is produced at a time.
The operating instructions clearly describe and explain the mixing ratio of gasoline and oil. Strict observance of the correct proportions will at least save you from several questions about why the petrol cutter will not start and what to do in such cases.

The petrol cutter will not start or will start, but stalls. What is the reason?

To understand this, you need to know the principle of operation of the unit as a whole. It also happens that, just bought, a new saw does not start, and it starts running around the service centers, in such cases it is recommended:

Carefully read the instruction manual;
to study in detail the method of the first start-up and running-in of petrol cutters;
try to understand how the product works;
how gasoline is pumped up and so on.

Reasons for malfunction of petrol cutters:

The quality of gasoline is poor;
incorrect proportion of gasoline and oil;
clogging of the fine filter;
the spark was gone.

The benzokos does not start when hot

If the brushcutter was recently in operation and has not yet had time to cool down but does not want to start, press the gas trigger, pull the starter cord sharply several times until the engine starts and only then the gas trigger is released. If enough time has passed and the brushcutter has managed to cool down, then it is necessary to start it as if it were cold.

Checking the condition of the fuel and air filters.

If everything is in order with the fuel quality, the chainsaw engine may not start due to clogged fuel and air filters. To diagnose these elements, it will be necessary to perform a number of manipulations associated with their dismantling.

For the fuel filter:

1. Disconnect the gasoline supply channel from the carburetor;
2. Pump up fuel.

If there is little or no pressure in the pipe, disconnect the filter. Before this, free the tank from the mixture and remove the filter element itself. Dismantling is done with a wire hook. A clogged replacement cartridge that causes a poor starting of the chainsaw engine can be cleaned, but it is best to replace it with a new one. When operating the tool in dusty conditions, it should be cleaned on a regular basis.

A clogged air filter can cause the chainsaw engine to run erratically, making it stalling or difficult to start. Dust and dirt deposited on the adsorbent material impedes the flow of air into the system, making the fuel mixture so rich that starting the tool will sometimes be difficult.

Checking the air filter is one of the first steps in finding the cause of a poor start.

Care must be taken when removing the air filter, as dust accumulated on the surface of the saw during operation can enter the carburetor. And this is fraught with more expensive repairs. After detaching the cartridge, thoroughly clean it from the accumulated dirt and rinse it with the addition of detergent. Dry the element and place it in place just as carefully.

Finding reasons why your chainsaw won’t start

Amateur and professional chainsaws are complex devices. The service life of their two-stroke engines, components and assemblies has its limitations. For this reason, quite reliable and expensive tools, along with cheap Chinese units, periodically fail and refuse to start. The situation when the chainsaw does not start or stalls is not very pleasant and sometimes confuses the user. How to identify and correct a malfunction by returning the instrument to work.

• Identification and elimination of obvious malfunctions of the chainsaw.
• Checking the spark on the spark plug and eliminating the cause.
• We determine the availability of fuel and its supply.
• Checking the condition of the fuel and air filters.
• Checking the breather and cleaning it.
• Checking the outlet of the chainsaw.
• What if the chainsaw won’t start further?

Checking the outlet of the chainsaw.

One of the reasons that a chainsaw does not start well may be a clogged exhaust channel or its muffler. At the same time, a drop in power is noted in the process of sawing sawn timber and logs. This is most often due to resinous deposits on the spark arrestor or muffler channel, which are formed during the combustion of a poor-quality mixture of gasoline and oil, which impede the removal of exhaust gases.

Resonator clogged with carbon deposits can cause poor starting of the gasoline saw.

Eliminate the reason for the poor start of the chainsaw, in this case, you can remove the accumulated combustion products. To do this, perform a number of manipulations:

• Remove the muffler by unscrewing the screws;
• Remove the cooling panel and gasket;
• Remove the spark arrester;
• Disassemble the resonator housing;
• Wash all elements from carbon deposits with detergent;
• Let them dry completely;
• Collect everything in reverse order;

Checking the breather and cleaning it.

The breather is another element, from the improper operation of which the chainsaw may not start or stall during the sawing process. This element is located on the fuel tank cap in the area of ​​the air hole. This is a kind of valve that prevents gasoline from flowing out and equalizes the air pressure required for the free flow of fuel into the carburetor.

If the breather is dirty, the working chainsaw stalls, and when it starts it refuses to start. The thing is that air stops flowing through the hole. As a result, a negative pressure (vacuum) is created inside the fuel tank, preventing the flow of gasoline to the carburetor.

Defining the problem is pretty straightforward. Disconnect the fuel hose from the carburetor and see what happens to the gasoline. If it flows out without hindrance in a good trickle, then everything is in order with the breather. If it is absent or it flows weakly and intermittently, then the reason is identified the breather is clogged with dirt. You can solve the problem by cleaning the air hole with a regular needle or a powerful jet of compressed air.

We determine the availability of fuel and its supply.

First you need to make sure that there is a fuel mixture in the tank of a chainsaw that does not want to start, and it regularly enters the carburetor. With a full tank, we check how the mixture is fed through the gas line. Disconnect the fuel system pipe from the carburetor and try to pump it up. In the case of a complete order, when pumping, gasoline will be supplied in jerks in accordance with the standards set by the manufacturer. Poor or no fuel supply can result from:

• The fuel supply channel is clogged;
• Clogged fuel filter.

Often the reason for a poor start of the chainsaw can be a tank that is too full. In this case, you should pay attention to the presence of smudges under the saw case cover. If present, see the connection of the gasoline feed pipe to the carburetor. Most often, it is squeezed out by pressure when the tank cap is screwed on, filled up to the very neck, which prevents the engine from starting.

The quality of the fuel mixture can also be one of the reasons why the chainsaw does not start. If, after completing the work, the remaining gasoline is not drained, and the tool is left for long-term storage (more than 2 weeks), then the processes of gum formation and polymerization of components will begin to occur inside the tank. What can cause carbon deposits on the piston, rings and cylinder liner. Therefore, always prepare the mixture only in the required amount before work.

Checking the spark on the spark plug and eliminating the cause.

The first step in looking for reasons why your gasoline saw won’t start is to check the spark on the spark plug. There are many factors that affect the performance of this element. However, the main ones at the initial stage of instrument troubleshooting are:

• Incorrect carburetor adjustment;
• The presence of more than it should be, the amount of oil in gasoline;
• Clogged air filter.

All of them contribute to the formation of carbon deposits on the spark plug electrodes. In 50 cases out of 100, the saws do not start on a cold one due to the absence of a spark due to carbon deposits on the electrodes and their corrosion. As a result, the gap either decreases or increases.

Checking the spark plug with an idle chainsaw

It is quite easy to check for a spark. This will require:

• Remove the tip of the high-voltage wire;
• Unscrew the candle;
• Put the tip back on;
• Lean the candle with a skirt against the cylinder;
• Start with a starter.

If a good spark is observed between the electrodes at the time the chainsaw engine starts, then everything is in order with the ignition unit. If it is not there, then it is worth cleaning the element itself and checking the gap of the electrodes. If necessary, use a special probe to adjust the distance between the contacts.

There may be no spark on the spark plug for other reasons. Of the main faults affecting the poor start of the chainsaw and the unstable operation of the internal combustion engine at idle, from which the tool can stall, the following can be attributed:

• Overflow of the spark plug channel with fuel;
• Lack of contact between the high-voltage cradle and the tip of the candle;
• Failure of the ignition unit.

How to start a cold chainsaw if the candle channel is constantly flooding with gasoline? To eliminate the problem while starting the tool, you can use the following algorithm:

• Unscrew the candle with a special key;
• Wipe it with a clean and dry cloth;
• Dry for 2030 minutes;
• Remove carbon deposits with a file and adjust the gap between the electrodes;
• Drain the remaining fuel from the spark plug channel and dry it;
• Collect everything and try to start the mechanism.

If there is no spark with poor contact of the high-voltage cradle with the spark plug tip, check the connection. The check can be done using a conventional tester. If a defect is found and its elimination, the chainsaw should start without any problems.

If the check showed that the contact is reliable, and the saw will not start further, look for the cause in the ignition unit. As a rule, a faulty unit cannot be repaired or restored. It will require a complete replacement.

Checking the fuel mixture

Before starting the engine of the gasoline streamer, check the presence and quality of the fuel mixture. Do not save, do not be greedy and do not be clever in this matter. Repair or replacement of the piston group will cost you too much (sometimes up to 70% of the cost of a new tool). Prepare the oil-fuel mixture strictly according to the instructions. Calculate its amount based on real needs. Excess gasoline left over after work loses its quality over time.

Diagnostics of filters for petrol cutters

Another reason why the gasoline scythe stalls is the air filter. To eliminate it, try removing the filter and starting the trimmer without it. If possible, then you will have to change the air filter to a new one, or at least blow through and thoroughly clean the old one.

The petrol trimmer may not start if the fuel filter is dirty. This is the next step in our algorithm. Here we check the condition of the filter element and, if necessary, replace it with a new one. When replacing, try not to leave the suction pipe completely without a filter, this is prohibited by any operating instructions. Haste can turn into repairing the engine piston group.

How to start diagnostics of brushcutters

If the brushcutter does not start or immediately stalls after starting, it is necessary to sequentially check all the main components and assemblies. The verification algorithm is as follows:

• Fuel tank (fuel quality);
• Candle and candle channel;
• Air filter;
• Fuel filter;
• Breather;
• Outlet channel.

These nodes are most often the source of major problems that can be eliminated after a thorough inspection.

Breather and exhaust port

Often, delicate branded petrol brushes do not start and stall due to a dirty breather. The main function of this element is to equalize the pressure in the gas tank. When this unit becomes clogged, a vacuum is created in the tank, preventing the supply of fuel. You can eliminate the malfunction by cleaning the breather. You can use a regular needle for cleaning.

Normal operation of streamers with internal combustion engines can be disrupted due to dirt entering the exhaust channel or a clogged silencer mesh. There is such a problem on older generation models. The issue can be resolved by traditional cleaning and removal of the anti-spark grid.

Why the petrol cutter won’t start troubleshooting

Caring for the personal plot, summer residents periodically encounter the fact that the petrol cutter does not start. There are many reasons for tool failure. For the correct diagnosis of the problem, the owner of a useful unit in the country needs to know the device and the principle of operation of its individual parts.

• How to start diagnostics of brushcutters
• Checking the fuel mixture
• We carry out diagnostics of a candle and a candle channel
• Diagnostics of filters for petrol cutters
• Breather and exhaust port
• Complex reasons for the failure of petrol cutters
• Rules for the operation and storage of petrol cutters

Complex reasons for the failure of petrol cutters

If the step-by-step troubleshooting algorithm does not work, and your scythe still does not start or stalls, it is worth inspecting the carburetor and the engine itself. A clogged carburetor can be one of the reasons for erratic tool performance. There are three main problems here:

• Clogged ducts or nozzles. All this is cleaned by special washes or blown by a powerful jet of compressed air from the compressor. Do not use needles and wires, as the bore may be damaged;
• Worn carburetor gasket. Exit replacement of a failed gasket;
• Violation of tightness. To check this indicator, you can use an ordinary household tonometer, replacing it with a suitable pressure gauge. Watch the readings: if they do not change everything is fine, but if the pressure starts to drop, then some part of the carburetor is faulty. We’ll have to find it and replace it with a new one.

If everything is in order with the carburetor, then the petrol trimmer may not start due to wear of the piston group. If chips, scratches or scuffs are found, the piston or cylinder should be replaced. Piston rings are subject to mandatory checks. A small backlash of the piston when rocking the connecting rod indicates that it is time to change the rings. It is best to entrust this procedure to the specialists of the service center.

What to do if the petrol lawn mower won’t start?

The most important point when using any equipment is to comply with the basic rules of operation and its timely maintenance. This approach will ensure that your petrol lawn mower is working properly and for a long time. Still, sometimes unforeseen situations happen, and the device for some reason does not want to start. In our article, we will tell you about the possible causes and solutions to such a problem.

Faults that you can correct yourself

When your petrol lawnmower will not start, the first step is to check for fuel in the tank. If it is missing. Top up to the desired level. Often, when the device is not used for a long time, gasoline runs out, so it must be completely drained and refilled with new. This procedure must be done carefully so that fuel does not get onto the engine, as this can lead to ignition in the future (when the engine heats up). Which gasoline is better to use, you can find out from the technical passport of the device.

In order for the unit to start, you need to pump fuel with a primer (if available in this model) into the carburetor and set the maximum speed. You need to start the technique carefully. The starter cord must be pulled out smoothly until it stops, and then pulled towards you with one even sharp movement.

A problem can occur if the air damper is not correctly positioned during the first start. Depending on the air temperature, it is completely closed or set to the middle position (above 30 C). Then it must be fully opened.

Check the air filter for dirt. To do this, turn off the machine and disconnect the wire from the spark plug. Unscrew the cover and remove the filter. Wash it with gasoline and dry it thoroughly, or just put a new one. Remember that it is recommended to change the air filter after every 25 hours of operation.

Another reason your petrol lawnmower won’t start could be a faulty spark plug. Perhaps she was just flooded with fuel. In this case, unscrew it, clean it and check for a spark. It may not be present when the spark plug is filled with fuel. Place choke control handle (if equipped) in the CLOSED position and start the engine. If this does not help, it is better to seek help from a specialist.

Try to constantly inspect the underside of the unit, as any damage to it may cause the engine to stall.

If your petrol lawn mower started up normally but stopped working almost immediately, it is likely that the crankshaft or piston is stuck. Another reason may be insufficient oil in the crankcase. We recommend manually moving these parts and checking the oil level with a special dipstick, you may be able to correct this problem.

However, remember that the replacement and repair of all faulty components and elements should be entrusted to professionals from authorized service centers. Never do it yourself.

If you want to talk with a specialist and get advice on the issue that has arisen, call us by phone: 7 (495) 135-29-39 every day from 10.00 to 20.00. We will provide all the information you need.