My Lawnmower Won't Start and Doesn't Even Make a Noise

Air Filter

• Often, when a lawnmower won't start and doesn't even make a noise, there's a problem in the mower's carburetor. If your lawnmower won't start up, check the air filter first. If the air filter in your lawnmower is clogged up, air can't get to the engine's carburetor. If the carburetor can't get air, it won't be able to push gas into the engine. Clean or replace your lawnmower's air filter about every two years.

Fuel System

• Trouble in a lawnmower's fuel system can originate in several different areas. For example, if your lawnmower's gas cap is clogged, the mower's fuel tank will develop vapor lock. Vapor lock in a lawnmower's fuel tank prevents fuel from flowing through the fuel lines. Also, a clogged fuel line on a mower will prevent it from starting up. Clogged fuel filters and gummed up carburetors also prevent lawnmowers from starting, especially if carburetor floats are stuck.

Other Problem Areas

• When a lawnmower refuses to start up, the issue could be as simple as a stuck choke or a poorly adjusted throttle cable. If your mower's choke won't close all the way, the engine won't be able to draw gas. A lawnmower throttle cable that can't move smoothly often prevents the choke from working properly. Some lawnmowers also come with oil sensors; and if the oil in the mower isn't kept at the fill line, these mowers will refuse to start.

Considerations

• Always make sure you have fresh gas in your mower's fuel tank. Stale gas is a common problem when a mower won't start. Gas ignites easily, so keep your mower away from sources of heat, flame or sparks. After checking your mower's air and fuel system, check its spark plug for fouling as well as its safety system. Most lawnmowers have at least one safety switch that will prevent the spark plug from creating a spark if the switch is tripped.