Lawn Mower Won’T Start Reasons

The lawn mower will not start, or starts but stalls The lawn mower will not start, or starts 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 starts and stalls. What to do?

1. There is a spark, and everything seems to be normal, but the mower will not start, in such cases you should check the air inlet 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 lawn mower will start, but then stall. To exclude this reason, you need to clean the valve and try to start the lawn mower with the tank cap not completely twisted.
2. If this does not start the mower, remove and clean the fuel filter and check all carburetor parts, then try starting. The lawn mower 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 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.

Is everything whole, clean, working?

Trying to adjust. We take a long screwdriver, find the idle speed adjustment bolt (it is located on the throttle valve), twist it a couple of turns so that the damper opens slightly. We start. Does it work smoothly? Then let’s move on. Won’t start or stall? Opens the damper until it starts up stably.

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Next, adjust the quality of the mixture with screw L. It is necessary to achieve maximum idle speed. Here the principle is reversed. The more the bolt is unscrewed, the richer the mixture. After that, the quality of the mixture is adjusted at maximum speed with screw H.

If the carburetor adjustment does not work, then it needs to be disassembled. Watch the membrane, clean the jets and internal passages. For this, it is necessary not only to have a repair kit, but also, preferably, a spare carburetor.

Lawnmower won’t start: causes and remedies

Diagnostics of the reasons why the lawn mower won’t start. A quick return to life of Chinese and domestic two-stroke internal combustion engine lawn mowers.

It happens that a two-stroke motor does not even show a flash in the cylinder, but sometimes it catches it and immediately stalls. No need to be sad, this Chinese commodity can be repaired right on the knee with a minimum of tools.

Before starting diagnostics, you need to make sure that the motor rotates with little resistance. If there is no compression in it, then the further is useless, and the piston needs to be changed (there is nothing complicated about this either, everything is like a designer).

The first is the candle

The first step is to unscrew the candle. If it is wet, the ignition system is faulty. Try to wipe off the spark plug, put it in the cap, attach it to the engine, pull with the starter. Is there a spark? If not, then you need to change the candle.

Replacing the spark plug didn’t help? Then you need to watch the magneto, cable, ignition coil. The cable is ringed, the coil is checked for resistance (the multimeter is in the resistance measurement mode at 200 Ohms, one contact to ground, the other to the output of the coil, should show from 0.4 to 2 Ohms).
Sometimes the magnets on the flywheel get dirty, or the key is licked off, and the ignition moment flies away. Chinese shit throws up all sorts of surprises, but most of it can be revealed visually.

Be sure to pay attention to the plaque of the candle. If it is black, the candle is smoked, then the mixture is rich, or you have mixed the fuel incorrectly. If the plaque is white, it means that the mixture is poor, and the engine could already die of temperature. Ideally, the color should be brick, light, without much plaque.

Again, if the black candle is dead, you should not immediately sin on the carburetor and ignition. Screw in a new one, see what the plaque will be. Maybe the candle was just of poor quality.

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.
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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.

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.

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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.

lawn mower won't start reasons

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.

  • 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.