Lawn Mower Does Not Start

The lawn mower won’t start, or starts but stalls
The lawn mower will not start, or will start but stalls. What is the reason?

The lawn mower 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 the wire to it, put the candle sideways to the motor casing and pull the starter several times as if starting the lawn mower, 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 lawn mower will not start on a cold

When starting a cold engine, it is not recommended to press the gas. Tilting the mower 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 lawn mower 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 first starting and running in lawn mowers;
try to understand how the product works;
how gasoline is pumped up and so on.

Causes of malfunctioning lawn mowers:

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

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 resin formation and polymerization of components will begin to occur inside the tank. Which can cause carbon deposits on the piston, rings and cylinder liner. Therefore, always prepare the mixture only in the required amount before work.

Identification and elimination of obvious malfunctions of the chainsaw.

To determine the reason why the chainsaw does not start or stalls when starting, it is necessary to troubleshoot the tool. The essence of the procedure is to consistently inspect the condition and operation of the main working elements of the saw motor. At this stage, we check:

  • Spark plug present;
  • Fuel supply;
  • Filter status;
  • The operation of the breather of the stalling unit built into the fuel cap;
  • Functioning of the outlet channel.

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.

Insufficient chain lubrication prevents starting and the saw does not develop speed

Many people ask themselves: why the chainsaw stalls when I press the gas? The answer may also lie in insufficient chain lubrication (see oil for the chainsaw chain), since the oil line may leak, or the direct channels may simply be clogged. That is why pay attention to the chain, since if it is dry, then, without delay, start cleaning the channels that supply oil directly to the tool tire. After that, inspect in detail the parts where the oil pump fittings are connected to the pipes. But if you notice that the oil leaks at the joints, or found cracks on the pipes themselves, then in the first case, seal the leaks with a sealant, and the pipes will have to be replaced.

Filling the mixture when the mechanism is running

Direct damage can also be caused by pouring the mixture into a candle at the moment when the mechanism is started. In order to solve this problem, it is necessary to turn out and dry the candle, but remember that it should never be ignited. Excess fuel must be drained through the hole (plug), wait 20-30 minutes, then put it back in place and try to start the tool again.

Why does the chainsaw stall when you give gas when pressed, and does not start under load at idle

There are often cases when the owners of chainsaws are faced with their breakdown and it does not matter which model of this kind of equipment, since the nature of the breakdowns is almost the same for everyone. Well, the chainsaw has stalled and what’s next? Undoubtedly, you can refer the technique to specialized services that will repair your "iron friend" for a fee. But as the saying goes: why pay more?

After all, you can personally disassemble the tool and repair it, since the breakdown may be insignificant, and in the service you will pay a lot for this. But naturally, in order to bring the instrument back to life yourself, you need to be able to understand the reasons for its breakdown and how to troubleshoot it. So let’s learn! In this article, you can find answers to questions related to situations when the instrument simply stalls after directly pressing the gas. So let’s get started.

Why the lawn mower won’t start – troubleshooting

Caring for a personal plot, summer residents periodically encounter the fact that the lawn mower 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.

lawn mower does not start

  • How to start diagnosing lawn mowers
  • Checking the fuel mixture
  • We carry out diagnostics of a candle and a candle channel
  • Lawn mowers filter diagnostics
  • Breather and exhaust port
  • complex reasons for lawn mowers failure
  • Rules for the operation and storage of lawn mowers

We carry out diagnostics of a candle and a candle channel

If the quality of the fuel mixture is not in doubt, and the lawn mower stalls when started, then a flooded candle may be the cause. Here, for repairs, an ordinary spark plug wrench (probably every motorist has) and a spare candle are suitable.

  • We unscrew the candle and wipe it;
  • Dry it thoroughly (do not ignite);
  • We drain the excess fuel in the chamber through the spark plug hole and dry it;
  • We clean the old candle from carbon deposits using a file or a lady’s file;
  • We expose a gap with a distance of 1 mm (you can check with any coin);
  • We put everything back in place and try to start the trimmer.

If the candle is working, the socket where it is located is completely dry, and the lawn mower does not want to start, lubricate the threaded connection with gasoline. It should be slightly damp. No matter how wonderful a spark the candle may give out, there is simply nothing to ignite in a dry chamber.

If the trimmer motor still does not start, you should exclude such a reason as the absence of a spark due to poor contact between the spark plugs and the high-voltage wire. If the connection is of good quality, but there is still no spark, most likely, your ignition unit has "flown". Here it will not be possible to do without a master, since the part is not repaired, but sold as a single unit.

Breather and exhaust port

Often, "gentle" branded lawn mowers 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, which prevents 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.