Lawn Mower Is Not Starting
Common Causes & Fixes
Lawn Mower is not Starting
In this blog, we are going to discuss the most common causes of why a lawn mower does not start. Why a gas lawn mower won’t start that easily usually during the cold season. The surrounding temperature can also play a big part not only in the performance of the engine but also with its starting process. On the other hand, there are also some typical causes why hard starting occurs.
5 Common Causes Why a Lawn Mower Does Not Start & Best Solutions
Lawn mower is hard to start –
Bad Gas in the Tank
If your problem is your lawnmower is hard to start or ultimately the lawnmower is not starting at all, this could mean that the dirt in the old gas is causing the blockages. Insufficient distribution of gas to the carburetor, flooding in the carburetor, and the improper mixture of air which can result in hard starting, engine stalling, and sputtering are some of the symptoms of blockage due to bad gas.
There are two ways to drain out the gas from a lawn mower but make sure before you do these you should disengage the spark plug first. The first is by tilting the machine on the opposite side of the air filter to prevent it from getting saturated with gas. Remove the gas tank cap and tip the gas to a container. Second, use a hand siphon which is much safer and quicker. You only need to insert the first tube of the siphon into the tank down to the bottom and let the other tube hang into the container then pump the tool 3 or 4 times and the gas will automatically flow out through the hose.
After draining all the gas out, keep the machine in your garage and when you’re about to use it, don’t forget to mix the gas with a fuel stabilizer and follow the right gas-stabilizer ratio written on the product’s label. Learn How to Winterize a Lawn Mower here
Bad Spark Plug
Several signs could tell you if your lawnmower’s spark plug is bad. The first sign that you will notice is hard starting. Second, the lawnmower will start after much pulling then will die before it runs. And lastly, the engine may stall while running. To check the condition of the spark plug, undo it from its seat and check. Turn it anti clockwise to undo it ,but be careful not to cross thread it when reinstalling. You may see some corrosion or carbon deposits or even oil and gas on its terminal. If this is the case, a replacement would be necessary.
If the spark plug is still looking good but you see some dirt deposits on its electrode and terminal, wipe the dirt off with a clean rag including the seat of the spark plug. Make sure the electrode which is the top coil that produces the spark is completely cleaned out. Then insert fine sandpaper between the side electrode (hooked wire) and the center electrode and slowly sand them until you see the dirt cleared out.
If you have a gap tool, measure the distance between the side and the center electrode and it should be at least .033 inches or 0.08 cm. Remember that too wide a gap, the electricity can not jump between the electrodes. And with a too narrow gap, the electrodes would not produce the spark. Spark plugs are designed for about 25 hours of use or longer for branded ones.
If the carburetor becomes flooded with gas because the needle valve is partially blocked, the carburetor would not be able to produce the proper air-fuel mixture and the combustion in the combustion chamber may go haywire.
You can see some signs of a flooded carburetor such as the smell of gasoline and see drips coming out from the carburetor while the smoke that will come out of the exhaust can be white smoke which tells you that your engine is having a richer mixture of gas than air. The engine may also sputter or stall.
The best thing to do when a lawn mower does not start because its carburetor gets clogged is to drain out all the gas from the tank and disconnect it. Take the carb off your mower. Clean everything inside it including the small parts like the needle valve and the float valve including the inlet and outlet hoses where the fuel comes in and out.
Use a carb cleaner to dissolve soft blockage inside of the carburetor and check also the nut that’s holding the carburetor cup found at the bottom of the carburetor. This nut also has a hole in it that regulates the air pressure inside the carburetor.
Dirty Fuel Filter
The most common symptoms of a clogged fuel filter can be sputtering of the engine when starting, hard starting, constant idling of the engine, lack of acceleration, or the lawn mower does not start even with strong and repeated pulling.
The lawn mower’s fuel filters are made of 2 types: metallic and paper/nylon filters. For the metallic ones, you need to disengage them from the fuel line, drain the fuel from them and spray with carp cleaner thoroughly. Once the carb cleaner dries, blow on one end to eject any sediments that are inside it. But if the filter still looks dirty, replace it with a new one. With the paper/nylon filters, these are disposable so once they are clogged badly, you have to replace them.
Dirty Air Filter
Three main types of lawn mower air filters are: the foam filters, paper air filters, and dual filters that have paper and foam components.
Because there will be a decrease of airflow to the engine due to a dirty or clogged air filter, the signs can include hard starting, engine stalling, sputtering, loss of power, and increased fuel consumption. There could also be black smoke that will come out from the exhaust.
Air filters are generally easy to detach from their holders thus easy to know when they are clogged or damaged. To clean air filters, the foam types even if they get soaked with oil and debris can be cleaned under running water then apply detergent soap, lather them up by squeezing them, then rinse under running water again. But if the foam is worn out, better replace it.
With the dual and paper type air filters, once they get soaked with carbon and grease, better replace them altogether. But if only dry dust is clogging them , try brushing the dirt with a dry paintbrush or blow the dirt using an air compressor.
Failing Starter Solenoid
If you hear the click and the lawn mower is not starting, there could be a problem with the solenoid itself and it’s losing its connection and cannot send current to the starter motor.
The best way to answer the question – why won’t my lawnmower start when I hear a clicking sound with my riding lawnmower but nothing happens, that issue could be a starter solenoid problem. And by replacing this part could solve the problem of your lawnmower not starting. This part could be expensive but it would cost you more if you take your machine to a repair shop. If you can,ask a mechanic friend about the problem with your riding lawnmower and if he tells you it’s a solenoid problem then you could buy this part and install it yourself. This will save you money on repairs.
Now that you have learned some things about why a lawn mower is not starting, the next time your machine doesn’t want to start, just try some of our suggestions first before you take it to the repair shop.