There are three main reasons why a lawn mower will not start. This can be due to fuel issues, battery related or sparking problems. Conduct a few troubleshooting methods to narrow down these problems, which can often be corrected at home.
• Ethanol-based fuel will gel up and clog the carburetor if you fail to empty it at the end of each mowing season.
• Fuel that is currently in the lawn mower may not be properly mixed or otherwise bad. Siphon out the old fuel and replace it with fresh fuel.
• If the lawn mower has new fuel, check the carburetor to ensure that fuel is properly flowing to it. All fuel lines should be checked to make sure they are not loose, kinked or clogged.
• The fuel filter is an important component to the proper operation of the lawn mower. If the fuel filter is dirty, missing or clogged, the proper flow of fuel can be disrupted.
• The float within the carburetor can sometimes become stuck in the lawn mower. Slightly tapping on the carburetor can free the float and allow the fuel within the mower to flow better.
• When a lawn mower has a spark and is filled with fresh fuel and rolls over, it may mean that the battery needs charging.
• Battery cables can loosen up while sitting or from jarring that takes place during use. Make sure all battery cables are secure and tightened properly.
• After sitting for long periods of time, a battery may not want to hold a charge. This can be fixed by replacing the battery in the lawn mower.
• Problems that occur after sitting during cold weather seasons may signal a situation in which the spark plug wire has not been properly attached as needed.
• If the motor of the lawn mower does not turn over, this can be a sign of a bad spark plug. Remove the spark plug, and inspect it for debris or improper gapping. Replacing the spark plug when using it for the first time of the season can help this problem.
Refer to the owner’s manual to locate the right size spark plug needed and the recommended gapping of the spark plug for their specific lawn mower model.
• If spark is present within the motor of the lawn mower, this can mean that the mower needs new points or a new ignition module. This is determined again by the type and age of the lawn mower model.