Things You'll Need
3/8-inch drive ratchet and socket set
Philips head screwdriver or Torx hand driver
Small engine starting fluid
Always check the oil level before trying to start your lawnmower. Some lawnmowers have a built-in spark shut off, which is activated by a low oil level. Simply adding oil to the engine could eliminate the starting problem completely.
Use only small-engine starting fluid on a lawnmower, which is available at some hardware stores or any lawn mower repair facility. Standard engine starting fluid is too combustible and will ruin your engine.
Never use a fluid on an engine for anything other than its intended use. Starting fluid is highly flammable and should only be used to assist in starting a motor. Starting fluid should be kept away from excess heat, flame, sparks, static electrical charges and cigarette smoking.
Lawnmower engines are small in size compared to automobile engines, but they can be trickier than a vehicle engine when it comes to diagnostics. A push-mower or basic riding mower is usually equipped with a two-stroke or four-stroke engine, containing one or two cylinders. An engine that will not start could be the result of a multitude of symptoms, ranging from a bad spark plug to bad fuel. Adding starter fluid directly to the engine can help you diagnose why your lawnmower will not start.
Remove the air filter housing cover from the mower, using a screwdriver or Torx driver to loosen the mounting screw. For some models, you will need to remove the upper plastic engine cover, using a 3/8-inch drive ratchet and socket. Remove the air filter from the housing.
Remove the mounting hardware from the air filter housing, using a ratchet, screwdriver or Torx driver. Remove the air filter housing completely from your mower's engine.
Spray a light dose of starter fluid directly into the carburetor chamber of your mower. Set the engine speed to the midpoint, if the idle is adjustable, by hand. Set the engine choke to full choke, if equipped.
Start the mower by pulling the starter string or turning the electronic starter key. If the lawnmower starts for less than three seconds and then stalls, the carburetor needs to be adjusted, cleaned or replaced. If the mower starts for more than three seconds but less than 30 seconds, you may be looking at a case of bad fuel or water-saturated fuel.
Tim Petruccio is a professional writer and automotive mechanic. His writing combines more than 20 years of mechanical experience in automotive service, service management, automotive education and business ownership. He assisted in the automotive beta, which launched March 2011.