Lawn Mower Basic Troubleshooting Guide – It Won’t Start

You are enjoying your morning cup of coffee on your patio when something odd caught your attention as you gazed around your lawn . You were convinced it definitely needs some serious trimming. Your body felt good with the thought of having some exercise so you dragged your lawn mower from its parking space for a little work out. Then it happened. The mower refused to start. You give it some good pulling and prodding but it just does’t start. Not even a sputter. You felt frustrated. But before you push that lawn mower back to its parking space, you may want to try some of the basic trouble shooting steps that might address the reason for it not to start.

Before you start any troubleshooting steps, make sure that you are up to the task. If you haven’t done any kind of repair before, then you might seriously consider having a professional repairman do the job. Read our safety precautions when doing lawn mower troubleshooting yourself.

Take note, however, that this information is only provided as a general guideline. Be certain to check the operator’s manual supplied with your equipment, or consult with a servicing dealer for more specific information.

 1.     Check the Fuel Tank – Engine won’t start without fuel in it. Make sure there is sufficient amount of fuel in the tank. Never put used or dirty fuel. Bad fuel is the common cause of the lawn mower failure to start.

fueling lawn mower tank

If there is enough fresh fuel in the tank but it does not start still, then…

2.     Check the Spark Plug – Spark plug bad contact causes failure of the engine to start. This happens when the spark plug becomes fouled and dirty causing it not to spark. If the spark plug looks fouled or dirty, replace it with new one.

bad lawn mower spark plugs

Bad spark plug

good spark plug

Good spark plug

If the spark plug is clean or replaced with new one but it does not start still, then…

3.     Check the Air Filter – Dirty or clogged air filter cannot supply enough air needed for the engine to start. Remove the air filter and clean it or replace it with new one if it is already worn out.

lawn mower air filter

Clean and dirty air filter. Check your owner’s manual for specific kind of filter for your equipment.

If the air filter is clean but it does not start still, then…

4.     Check the Fuel Filter – Clogged or dirty restricts the supply of fuel to the engine causing it not to start. Clean the fuel filter or better yet replace it with new one. You also need to check the fuel line for any dirt build up.

mower fuel filter

Check your owner’s manual for specific type of fuel filter for your equipment.

If the fuel filter is clean and the fuel line is not clogged but it does not start still, then…

5.    Check the Carburetor – See if the carburetor is gummed up. Clean the dirt build up.  Check if there is gas flowing in to the carburetor.  If none, there might be a piece of trash in the needle & seat.  The needle & seat controls the gas flow that starts & stops the gas. You will have to clean or replace.

mower carburetor

After having performed the forgoing list of troubleshooting guides but still, your lawn mower does not start, then make an assessment how old your lawn mower is. It might be that it was purchased by your grandpa four decades ago and it has already reached its lifespan. Otherwise, it is more prudent to let a professional lawn mower repairman check the mower as they are adept in diagnosing all lawn mower start up problems.

LawnEQ has wide array of lawn mower parts for all types of lawn mowers at very reasonable prices.  Purchase authentic OEM Parts from the LawnEQ OEM Parts Lookup Store today!

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