Lawn Mower Does Not Start Well

Does your lawn mower start poorly? Adjust Magneto Gap

As the experience of operating lawn mowers, in particular, made in China, shows, they often have problems in the starting system, so they are often difficult to start. Problems are usually associated with flywheel magneto.

For those who are unfamiliar with this unit, we remind you: this system consisting of an ignition coil, spark plug and flywheel with magnets.

We have to deal with the magneto gap, more precisely, with the ignition coil gap and its guaranteed setting. It is because of him that problems arise in Chinese units, which for several years have been operated in domestic conditions or in the housing office.

But it happens that even in new products it is difficult to start, especially on a cold one. Again, starting problems are usually related to the magneto gap. Most people who operate lawn mowers set a magneto gap of 0.4 mm, as recommended by many manufacturers.

What happens if this gap is adjusted and set to 0.25 mm? It turns out that when it decreases, the electric spark becomes thinner, smaller and works out every stroke even at slow turns of the magneto flywheel.

That is, by deliberately reducing the gap, we, thereby, increase the likelihood of a normal start of the lawn mowers without any unnecessary physical exertion and shortness of breath, even when starting a cold engine.

The gap and the order of its setting in different cases

As a template for setting the magneto gap, you can successfully use a strip of the required width and length, cut from a regular plastic bottle, for example, from a Pepsi-Cola.

Only it is necessary to install it last, so as not to damage it during repair work, using the same hair dryer for any purpose. After all, if it warps from exposure to hot air, then there is no need to talk about the accuracy of setting the magneto gap.

It is with the help of a spacer cut from a plastic bottle that you can set the magneto gap of 0.25 mm with high accuracy, since its thickness is exactly the same. To make sure of this, it is enough to fold the strip in four and measure its total thickness with a vernier caliper, which will be exactly 1.0 mm.

We put a spacer cut from a plastic bottle on the magnets of the magneto flywheel, install the ignition coil in place and fix it with strong 8 by 8 bolts, having previously filled the threaded holes on the body with a threaded lock.

We apply it to the bolts, tightening which, you must not forget to fix the mass terminal. It is better to use a screwdriver for this. We push the bolts to the limit by hand with an ordinary hand-held screwdriver with a hexagonal bit, since the use of an L-shaped hexagon can lead to tearing of the edges of the bolt heads.

It remains, by turning the flywheel with magnets, remove the plastic spacer and, continuing to rotate it, check the quality (uniformity) of the gap when it is turned from 0 to 360 degrees, which with this approach turns out to be ideal.

Some people use a copier sheet folded in half to set the magneto gap, which is also acceptable, but using a spacer from a plastic bottle gives the best result. over, it can be reused dozens of times.

It remains only to install the body parts and you can start the engine to test how it starts and works.

Sometimes, during operation, the attachment points of the ignition coil to the magneto body are deformed, which does not allow it to be installed reliably, since the holes in the coil and on the engine body do not match.

You can, of course, try to correct the defect, but it will be safer to install a new coil, especially since it is not too expensive.

All further actions are similar to the case described above, except that the heads of fastening the bolts of the ignition coil may not be for a hexagon, but for a wrench and a Phillips screwdriver. But this does not change the essence of the matter: the tightening of these bolts must be guaranteed to be reliable, as in the first case.

To assess the quality of the work done, you need to make sure that there is a spark between the spark plug electrodes visually after the final assembly of the engine. To do this, we connect it to the ground and begin to turn the engine using a manual or electric starting device.

The spark test has one nuance. If you pull the kick starter sharply, then a spark will appear even with slightly faulty magneto magnets and even completely inoperative ignition coils. In this case, the presence of a spark is not yet an indicator of the health of the ignition system.

The quality of sparking can only be judged when it appears, when the magneto flywheel does not rotate too quickly, for which the kick starter should not be pulled, but pulled evenly and slowly.

Only in this case, the engine of the petrol trimmer or chainsaw will start without problems, both the first time in the morning and during the entire working day (respectively, the so-called hot or cold start).

If, however, a spark is not observed with a slow movement of the starting device, then, most likely, you will have to change the ignition coil, set the magneto gap or change the spark plug.

The practice of setting clearance on lawn mowers and chainsaws described above has been fully justified for the past five years. There were no complaints from users after such a repair. This really helps when launching not only Chinese lawn mowers, but also European, and even branded.

On all units, regardless of manufacturer, setting the magneto gap of 0.25 mm instead of the 0.40 mm recommended by the manufacturers gives excellent results. Some people suggest 0.10-0.15mm gaps, but this is too small. After all, there is a certain thermal expansion of the parts of the ignition system, the body itself, the crankcase of a lawn mower or a chainsaw, and such a small gap can disappear altogether, which can lead to breakdown (burnout), first of all, of the ignition coils. Therefore, a clearance of 0.25 mm is optimal from all points of view.

The most common reasons a lawn mower won’t start

  • Poor quality fuel. What gasoline do you use for your scythe? STIHL and Husqvarna tools will not run on cheap fuel, they need at least 92 gallon fuel from a reputable gas station. It is not worth saving on gasoline, since the repair of the cylinder-piston group can be a third of the cost of the tool itself. When preparing the fuel mixture, observe the proportions of fuel and oil, which are indicated in the operating manual. Please note that gasoline mixed with oil will lose its properties over time, so it must be used within two weeks. Always keep the fuel mixture fresh!
  • Fuel filter in the tank. If the mower does not start, be sure to check the condition of the part. Please note that the inlet must not be left without a filter.
  • Have you checked everything you can and still won’t start the mower? You may have forgotten about the air filter. It must be removed, and then try to run the tool without it. Starts up? This means that you need to clean the old or install a new filter.
Lawn Mower Does Not Start Well

Lawn mowers start types

What needs to be done first? Squeeze the throttle lock and trigger trigger to set the throttle to the start position. Then we press the start button. Let go of the throttle lock, throttle trigger and start button. Thus, we have activated the throttling function. To return the engine to idle, press the throttle lock and throttle trigger again.

Cold start lawn mowers

Please note that you must not pull the throttle trigger before the engine starts and starts running.

  • We place the tool on a flat surface and slowly press the fuel pumping button up to 10 times, the number may vary depending on the model.
  • Then we set the lever of the start system switch to the "START" position.
  • Pull the starter cord sharply until the engine starts.
  • Run the power pack for 5-10 seconds and then pull the throttle trigger to disengage the starting system.

Starting a warm engine lawn mowers

  • Hold the throttle trigger pressed and do not release it until the engine runs evenly.
  • Pull the starter cord sharply and wait until the power unit starts. In this case, the trigger must be pressed.
  • A warm engine is started within 10 minutes after it has stopped. If more time has passed, then use the instructions for turning on the cold unit.

Starting the engine with a flooded spark plug

In this case, the power unit can be started by placing the starting system lever in the RUN position, the throttle trigger must be pressed. Then we pull the starter handle as many times as it takes to start the engine. If the power unit does not start for a long time, you should contact the service center for help.

Adjustment and tuning of the carburetor

The maximum and minimum engine speed, smooth idle speed are regulated by the carburetor. The stable operation of the lawn mower depends on the amount of the supplied combustible mixture and air, their ratio. The lawn mower will not start if the carburetor adjustment is not correct. The procedure for adjusting the device for supplying fuel at low speed (L), high speed (H) and idle (T) is regulated by the screws of the same name:

  • The chainsaw must run for at least 10 minutes, since the adjustment is carried out hot.
  • Screw H is turned smoothly to maximum speed, then turned by ¼, counterclockwise, reducing the speed of rotation of the engine shaft.
  • Idling is adjusted with the screw T, ensuring that the scythe does not rotate.
  • The screw L is adjusted, at first opening the maximum throttle, and then smoothly reducing the speed to stable minimum.

After adjustment, a serviceable carburetor with cleaned filters and a checked ignition must ensure the engine is running. In the event of a carburetor malfunction, after repairing it, you will need to adjust the feed system again before starting the lawn mower.

Rare breakdowns that prevent lawn mowers from working can be:

  • Rewind spring defective;
  • Broken or stuck starter pulley;
  • Defective starter assembly.

The most important malfunction, the elimination of which is associated with replacing the engine, may be the failure of the engine piston group. The cost of repairs will cost about 70% of the cost of the product. Understanding the reasons why the lawn mower won’t start will help:

The lawn mower will not start when hot

If the lawn mower 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 lawn mower has cooled down, then start it up as if it were cold. If the above methods did not help, the lawn mower did not start, then you should contact the service center.

The lawn mower does not start on a hot one, stalls when you press the gas, do it yourself repair,

The tool, despite its small size, is a complex technical device. If you study the operating instructions, it turns out that the reasons why the lawn mower does not start are known and removable. It is necessary to consistently eliminate the factors that make it difficult to start the tool. Usually start with more accessible nodes with an easy health check.

Why the lawn mower does not start well when cold

Trimmer Starts And Stalls Immediately Causes

In recent years, the gasoline trimmer has gained textbook status as one of the main tools in the arsenal of summer residents. And such actions are logical, because a motorized scythe allows you to quickly put your personal plot in order. But it happens that the trimmer does not start on hot and cool. In such situations, it is necessary to establish the cause of the malfunction without the help of others. Next, let’s figure out what to do if the trimmer won’t start. The premises that mostly lead to such troubles will be examined further.

Where to start diagnosing defects if the trimmer won’t start? In situations where the tool stalls immediately after starting, it is worth looking at the following units of the unit:

Specifically, the breakdown of the above locations for the most part leads to the fact that the trimmer does not start well. It is necessary to consider how to remove such problems.

Let’s say your trimmer won’t start. Then the beginning of everything is to check whether there is enough fuel in the tank, to additionally evaluate the quality of the fuel consistency. The motorized unit should only be refueled with high quality gasoline. It is recommended to use fuel with a grade not lower than AI-95. Filling the trimmer with fuel of unknown origin not purchased at a gas station can lead to frequent tool failures. This causes a breakdown of the cylinder-piston accounting system. Repairs under these circumstances often exceed the price of the device itself.

Why won’t the petrol trimmer start? Incorrect preparation of the fuel consistency, which consists of oil and gasoline, can also lead to this. The proportions in which the designated components are connected are indicated by the manufacturers in the trimmer instruction manual. It is highly discouraged to prepare a fuel mixture in large volumes, in other words, for the future. Indeed, with long-term savings, there is a loss of the determining parameters of the substance. If the trimmer does not start, you should drain the old fuel and use a freshly prepared fuel consistency.

The reason why the trimmer starts and stalls. Trimmer stalls: causes and troubleshooting

The lawn mower is a mobile, high-performance tool for beautifying home gardens and surrounding areas. With prolonged use, due to wear of parts or manufacturing defects, malfunctions occur, which lead to the trimmer stalling or not starting. Since this tool is a rather complex mechanism, there may be several reasons why the lawn mower stalls.

Why does the trimmer stall

There are two main ways to troubleshoot problems: transferring the braid to a specialized center or solving the issue with your own hands. The first option is suitable for those who are ready to pay a "tidy" sum to restore the unit’s working capacity, and the second one for those who have basic locksmith skills and can independently figure out the causes of breakdowns and ways to eliminate them.

Currently, it is customary to classify breakdowns for which the lawn mower stalls into the following categories:

  • Mechanical damage to the internal combustion engine crankcase, malfunctions of the cylinder-piston group (CPG);
  • Breakdowns associated with the supply of the fuel mixture (air filter, carburetor);
  • Malfunctions due to damaged tubes, hoses, cables or ignition circuit.

Trimmer ON COLD does not start well, what to do?

What to do if the applied fuel mixture is in perfect order, alas, as before, the petrol trimmer does not start? The prerequisites for the failure of the mechanism are variations, such as excessive moisture in the candle channel. To diagnose and eliminate the difficulty, you need to do the following:

  • Remove the candle. Wipe it painstakingly, and then dry it.
  • Drain off excess fuel in the chamber through the appropriate plug hole.
  • Clean an old candle if there is carbon deposits on its surface. To cope with the task will allow the use of an ordinary ladies’ nail file or a file.
  • To install the element in the area, set a gap of 1 mm. To check the parameter, it is enough to place any coin in the gap.
  • Assemble the multifunctional unit back.
  • Try to start the trimmer.

It is recommended to dry the candle channel at a minimum for half an hour. But do not resort to calcining its parts. After all, heating the spark plug leads to its final damage. What to do if the service of the multifunctional unit was carried out according to the above tips, but the trimmer does not start, a spark of course with all this? Here it is worth treating the threaded connection with gasoline. The latter does not need to be abundantly impregnated with fuel. It is only slightly moisturized. Such actions should be taken to ensure ignition. After all, no matter how strong a spark the candle gives, in a completely dry chamber there simply will not be anything to ignite.

Even if the trimmer does not start here, it is worth assessing the quality of the contact between the high-voltage wire and the candle. For which the design of the absence of a spark is intended (if there is a reliable connection between the designated elements), for sure, the discrepancy is caused by a breakdown of the ignition unit. In this situation, you will have to turn to the services of wizards who will reinstall the node.

The lawn mower stalls at high engine speeds

During operation, a situation arises when, when you press the fuel mixture supply button, the unit turns not increase, but decrease. A malfunction of this nature can be caused by:

Fuel hoses for lawn mowers with filter

  • By etching atmospheric air into the combustion chamber;
  • Problems with the circulation of the fuel mixture;
  • Clogged breather in the fuel tank cap (cleaning the hole with a fine sewing needle);
  • Incorrect carburetor adjustment.

When air is leaking during the operation of the internal combustion engine, it is necessary to check the tightness of the connection of the pipes and the integrity of the gaskets in the CPG. The problem with the circulation of the fuel mixture can be solved by removing blockages in the fuel pipes leading to the carburetor. If a vacuum occurs in the tank and the fuel mixture does not flow to the carburetor, it is enough to clean the breather with a thin needle and blow it with air.

Does the engine stall immediately after starting? Why is this happening

Another common prerequisite for which the trimmer won’t start is a blockage in the filter area. To confirm the hypothesis, it is enough to dismantle the indicated block and test the start-up of the unit without it. If the trimmer engine has started, most likely, you will have to create a change of the air filter, or at least perform a painstaking purge of the old one. If there is abundant contamination of the filter element, use the latest mesh. When resorting to similar actions, it is not recommended to leave the absorbing tube completely without a filter. After all, haste in our version leads to the need to repair the entire piston group of the engine unit.

Often, the engine of branded trim models stalls when the breather is clogged. The main task of the designated component is to equalize the pressure in the fuel tank. For which the design of contamination of the unit is intended, a vacuum appears here, which significantly complicates the supply of fuel. Removing the malfunction allows cleaning the breather with an ordinary sewing needle.