Why lawn mower stops running

Use a spark plug gauge to measure the gap between the two electrodes at the tip of your spark plug. Check for the specifications for your model to know the recommended size of the gap. If necessary, use a spark plug gauge to adjust the gap by gently bending the curved electrode. When the gap is correct, the gauge will drag a bit as you pull it through the gap. Now you can install the new plug and attach the spark plug lead.

Be careful not to over-tighten on installation. If you have never done this before, there are several videos online that can be of great assistance, but my advice is that as soon as it starts to feel snug, give it no more than another quarter turn to prevent damage. White smoke coming out of the engine is a tell-tale sign that excessive oil is the culprit.

If a lot of smoke is coming out, your mower might be running, but not for long. In this case, the excess oil will eventually drown out the engine and cause it to die.

This is actually an easy fix. If you have too much oil, you just need to drain some. You can use a siphon, or if you have a walk-behind mower you can tip your mower and drain the oil from the hole where you add it.

I check, and check again with the dipstick and gradually bring the level up to the proper place. If you have overfilled your oil tank, I advise that you use a dipstick to measure the amount of oil in the reservoir before removing it, and then again after to make sure you get the right level. Not enough oil is another and more serious problem, and you would not want to inadvertently trade one issue for another. After draining some oil and checking to see if you have an adequate amount, start the mower again.

If the mower fires and stays running without the billowing puffs of white smoke , you have corrected your problem. The average weekend warrior with limited knowledge on the matter will probably feel more comfortable hiring someone with the experience and the tools to get the job done right.

Some companies will send someone right to your home, or come to pick up your mower to save you time. If they are loose, too much air may enter the carburetor. A carburetor establishes the correct mix of fuel and air required for smooth mower operations. Inside this mechanism is an assortment of springs, floats, needle valves and spray jets that can clog or need replacing.

In addition, adjustment screws on the outside body of the carburetor adjust flow and engine idle. Unless you are familiar with carburetor adjustments or rebuilding carburetors, repairs to this assembly are best left for the professionals. Robert Korpella has been writing professionally since He is a certified Master Naturalist, regularly monitors stream water quality and is the editor of freshare.

Korpella's work has appeared in a variety of publications. He holds a bachelor's degree from the University of Arkansas. Home Guides Home Home Improvement. This will also block airflow to the fuel tank, causing the same tank vacuum issues.

Start the lawnmower and mow your lawn as you normally would. When the mower dies, remove the gas cap and reinstall it. This will allow air back into the fuel tank so fuel can flow again. Try to restart the mower. If the mower starts up again and continues to run you will know that the fuel cap is faulty and needs to be replaced. Find your Caps here. Sign up. Thank you! Your email, , has been added to our mailing list. We were unable to add your email to our mailing list.

Millions of Parts From Top Brands. Need Help? Customer Service. Learn which plants thrive in your Hardiness Zone with our new interactive map! Gasoline powered lawnmowers are pretty dependable, but can develop problems. It can be frustrating if a mower starts, then dies after running a few seconds. Fortunately, a homeowner can troubleshoot, diagnose and fix most of the problems which cause this. Troubleshooting should start with an owner's manual, which usually will have instructions for a specific brand.

Most mower engines, however, are similar and have the same basic troubleshooting routines. The most common cause of a mower failing to keep running is a clogged air filter.