What would cause a spark plug not to fire?
Loss of spark is caused by anything that prevents coil voltage from jumping the electrode gap at the end of the spark plug. This includes worn, fouled or damaged spark plugs, bad plug wires or a cracked distributor cap.
Considering this, why is my mower not getting spark?
Loose, Dirty or Disconnected Spark Plug in Your Lawn Mower: Check it out, clean off debris, re-connect and tighten. Dirty Air Filter: Clean or replace. Fuel Not Reaching the Engine: Tap the side of the carburetor to help the flow of gas. If this doesn't work, you might need a new fuel filter.
Keeping this in view, how do I know if my lawnmower coil is bad?
Start the mower when it is cold, and look through the window of the tester. Observe that there is a normal spark that allows the mower to run. One of the symptoms of a bad lawn mower ignition coil appears when you are mowing the lawn and the mower gets hot and literally shuts off.
Will a lawn mower start if the spark plug is bad?
A dirty or fouled spark plug can cause your lawn mower to not start. It can also work itself loose, causing issues. If the spark plug appears to be seated correctly but the engine doesn't start, a new one may be in order.Incorrectly gapped spark plugs could cause engine misfires. Corroded spark plugs could halt the spark altogether and, again, cause misfires. Broken spark plugs could, you guessed it, cause misfires AND if pieces of the ceramic enter the cylinder, could cause far worse issues down the road.The most common reason for why your riding mower will turn over but not start is likely due to bad gas or a dirty carburetor. You can usually fix the problem by removing and cleaning out the carburetor and making sure that your gas is fresh. There are carb cleaners you can purchase to help you with this.First, Confirm Your Engine Has No Spark:
- Disable the fuel system by removing the fuel pump fuse or relay.
- Insert a spark plug tester into the plug boot and ground it on a piece of metal on the engine.
- Finally, Have someone crank the engine and watch for spark.