If your lawnmower is running rough or is hard to start, it is likely that the spark plug is bad. Use a spark plug wrench to replace the plug in a few minutes.Continue Reading
Most mowers use plug wires that attach through a round metal cylinder that fits over the metal end of the plug. Pull the wire straight out from the engine to remove the electrode.
Prevent debris from falling into the hole by using a small brush to sweep it away before removing the plug.
Generally, plugs require a 13/16-inch or a 3/4-inch wrench. Place the wrench over the plug, and turn counterclockwise to loosen and remove it.
Replace the plug if it has broken porcelain or a burned electrode. Change the plug at the beginning of each mowing season or after every 100 hours of use.
Use a wire feeler gauge to check the plug gap. Most small engines require a 0.3-inch gap. You should feel a slight drag as you pull the wire through the plug gap. Use the prongs on the feeler gauge to adjust the electrode if necessary.
Insert the new plug into the hole and turn clockwise to tighten. Once the plug becomes snug, tighten another one-quarter turn. Push the plug wire onto the plug.
A spark plug socket is a specialized, deep-length socket designed to fit over the plug terminal and insulator while it grips the hex nut for removal. Most spark plug sockets come in two sizes: 5/8 inches and 13/16 inches, accommodating standard spark plug brands such as Bosch, Champion and NGK.Full Answer >
Some of the most common lawn mower engine problems are a dirty, disconnected or loose spark plug, dirty air filter, flooded engine, leaky gasket and carbon deposits in the combustion chamber. These problems can cause a mower to knock, overheat or simply not start.Full Answer >
To fix a lawn mower that is stalling during use, check the spark plug wire, replace the spark plug and clean the air screen and air filter. Drain and replace the fuel to ensure a contaminate is not causing the machine to stall, and then clean the blades thoroughly before using the lawn mower.Full Answer >
Lawn mower problems are commonly associated with loose, disconnected or dirty spark plugs, and to solve the problem, you must remove the spark plug and replace it with a new one. This can be done in minutes at a low cost.Full Answer >