What causes a lawn mower to misfire?

A worn, dirty, oily, or improperly gapped spark plug can cause a weak spark, and this can lead to a misfire. A quick way to check that the spark plug is functioning properly is to carefully remove the spark plug wire while the engine is running. If you hear a drop in the engine rpm, then the cylinder is fine.

How do I fix my lawn mower from sputtering?

How to Fix a Sputtering Lawnmower

1. Remove the cap of the gas tank and look in at the gas. Inspect the gas for signs of water.
2. Turn the mower over so the oil case is sitting under the carburetor.
3. Remove the screw holding the air filter cover in place.
4. Check the underside of the unit for caked on grass.

Why is my petrol mower sputtering?

Clogged or Dirty Air Filters It is one of the most common problems that cause lawnmowers to sputter. The mowers take the air from the surrounding through air filters and mix it with fuel inside the engine. So, if the air filter is clogged or dirty, it will affect the flow of air into the carburetor.

Why does my lawn mower sputter then die?

A Mower Has to Breathe Too much air can also cause problems for the engine. A bad cap on the gas tank is the first place to look. If the hole is restricted, the cap bent or the seal under the cap damaged, the engine may be getting too much or too little fuel. Replace the cap to solve sputtering and dying.

How do I know if my lawn mower coil is bad?

Replace the original wire with the in-line spark tester, and attempt to start the motor. Watch for the same intensity of a spark that you saw when the mower was cold, If there is little or no spark, the ignition coil is bad and needs replacement.

What causes cylinder misfires?

Damaged, worn, or bad spark plugs, or a weak ignition coil can cause a loss of spark, and therefore, a misfiring cylinder. If the fuel injector is clogged, dirty, or has an air leak, the low pressure will affect all of the cylinders, rather than just one cylinder.

What should I do if my riding lawn mower won’t run?

Replace the engine fuel filter if it’s damaged or clogged. If your riding lawn mower’s engine runs rough or won’t run, the fuel filter could be dirty. This repair guide and video show how to easily replace the fuel filter on your riding lawn mower in 15 minutes.

Why does my lawn mower not start when I put gas in?

Impurities in gasoline can clog the carburetor, preventing the engine from starting. Carburetor clogs can also cause the engine to run rough and the engine may stall when you try to drive the riding mower. Seals and gaskets in the carburetor eventually wear out and can leak gas.

How do I know if my lawn mower has fuel?

Some lawn mowers have an actual fuel gauge, while others do not. For those that don’t, you can take a quick peek inside the tank. You should also check the fuel line for clogs and take a look into the carburetor bowl to ensure that fuel is reaching that part of the engine.

How do you fix a lawn mower that starts then dies?

Lawn Mower Starts Then Dies – Here’s the Fix! 1 Determine the Fuel Status. First—and this may seem like a no-brainer, but bear with us—check the fuel levels. 2 Check for a Clogged Carburetor. Has it been a while since you last started up your lawn mower? 3 Test the Fuel Cap. 4 Replace the Spark Plug. 5 Final Thoughts.