Starting Issues with Your Mower? Check These Common Culprits
At The Mower Medics one of the most common calls we get is “My mower won’t start”. There are a number of reasons why your mower won’t start, and our job is to figure out which one it is and to fix it. We specialize in this sort of thing, and here are the most common reasons we see for a starting problem:
Carburetor Problems
One of the most frequent causes of starting issues with mowers is a clogged or dirty carburetor. The carburetor is responsible for mixing air and fuel in the correct ratio to provide a combustible mixture for the engine. A dirty carburetor can restrict the flow of air or fuel, making it difficult to start the mower. One solution is to clean the carburetor with a carb cleaner and a small wire brush. If cleaning the carburetor still does not work, you may need to rebuild or replace it.
Spark Plug Issues
A faulty spark plug is another common cause of starting issues with mowers. Symptoms of a bad spark plug include difficulty starting, rough idling, and poor performance. The spark plug may be fouled, corroded, or otherwise damaged. Remove the spark plug and check it for any signs of damage or wear. If needed, replace the spark plug with a new one that matches the manufacturer’s specifications.
Starter Solenoid Malfunction
The starter solenoid is responsible for engaging the starter motor to turn over the engine. If you turn the key and hear a clicking sound, but the engine doesn’t turn over, then there is likely an issue with the starter solenoid. You can test the starter solenoid by using a multimeter to check for continuity between the solenoid’s terminals. If there is no continuity, then the solenoid is defective and will need to be replaced. Sometimes this issue may involve just the solenoid, and sometimes it can involve both the solenoid and the starter.
Bad Gasoline
Old or contaminated gasoline can also cause problems starting your mower. Gasoline can go stale after a few months or become contaminated with debris or water that can clog the fuel system. To avoid these problems, always use fresh gasoline and add a fuel stabilizer if you plan to store the mower for an extended period. If you suspect that the gasoline is the problem, remove it from the tank and replace it with fresh fuel.
Bad Fuel Line: The fuel line on your mower can go bad for a number of reasons, including age, wear and tear, and exposure to heat or chemicals. One of the most common symptoms of a bad fuel line is a lack of fuel reaching the carburetor. This can cause your mower to sputter, stall, or not start up at all. Other signs include a leaky fuel line, the smell of gas around the mower, and visible cracks or damage to the line itself. Over time your fuel lines can become brittle, cracked or clogged. Gasoline that contains ethanol can cause rubber fuel lines to break down over time, accelerating this problem. The fix is to remove the old fuel line and replace it with a new one.
Fuel Solenoid: One relatively uncommon reason that your lawn mower might not be starting is a faulty fuel solenoid. The fuel solenoid is a device that controls the flow of fuel to the carburetor. If it fails, your lawn mower won’t be able to get the fuel it needs to start. One way to test if this is the issue is to turn your ignition switch on and listen for a clicking sound. If you don’t hear a click, the solenoid may need to be replaced.
Dirty Air Filter: Another potential culprit for a mower that won’t start is a dirty air filter. The air filter is responsible for keeping dirt and debris out of the engine. If it’s clogged with dirt and grass clippings, it can prevent the engine from getting the proper airflow it needs to start. In this case, you’ll need to remove the air filter and clean or replace it.
Clogged Fuel Filter: Your lawn mower’s fuel filter is responsible for keeping dirt and debris out of the fuel and preventing it from getting into the engine. If the filter becomes clogged, the fuel won’t be able to get to the carburetor, which can prevent the engine from starting. To fix this issue, you’ll need to locate the fuel filter and replace it if necessary.
Battery Problems: Although a dead battery might be an obvious cause for your mower’s failure to start, there are also other battery problems that can cause this issue. Check the battery terminals to make sure they’re clean and securely connected. If you notice corrosion on the terminals, you can clean them with a wire brush or a battery cleaning solution.
Faulty safety switches: Safety switches, such as the blade engagement or seat switch, can prevent the engine from starting. Over time these switches can corrode or simply begin to malfunction due to wear and tear. Since these are electrical components they are easily deteriorated by humidity and moisture. A safety switch that malfuncitions and fails to engage will prevent the mower from starting.
Other, less common reasons your mower may not start are low fuel, a bad fuse, or wiring that has gone bad (come lose or is corroding). Of these reasons bad wiring is often the most expensive item to fix.
A lawn mower that won’t start can be frustrating, but knowing some of the reasons can help troubleshoot the problem and get your mower running again. From a faulty fuel solenoid to a dirty air filter, there are many potential culprits. Be sure to perform regular maintenance on your lawn mower to prevent future issues from occurring. Happy mowing!