DIY: Checking Spark on a Small Engine
Difficulty Level
Tools/Supplies Needed:
• spark plug socket and ratchetProcedure:
• first remove the spark plug boot by twisting and pulling straight off• remove the spark plug using the appropriate size spark plug socket and ratchet
• insert the spark plug back into the boot and hold it onto a ground source
• do not have your hand in contact with the boot or end of the spark plug as you can risk getting a shock
• pull the engine over as if you were going to start it and inspect for a spark
• a bright blue spark indicated everything is working correctly
• a yellow spark indicated there is an issue
• no spark indicated there is an issue
Causes for poor or no spark:
• worn out spark plug• dirty spark plug
• poor spark plug wire or boot
• coil contacts need to be cleaned
• coil is worn out
• coil needs to be gaped correctly with flywheel magnets
• magnets worn out on flywheel
• magnets need to be cleaned on flywheel
• worn ignition points
• ignition points need cleaning
• ignition points need to be setup properly
• kill switch isn't working properly
Video tutorial on how to check the spark on a small engine such as a rototiller, lawn mower, garden tractor, weed eater, snowblower, boat motors, leaf blowers, chainsaws, generators, etc. A strong spark is one of the key aspects in order for an engine to run correctly. Weak sparks can cause issues such as poor performance, poor fuel economy, hard starts, rough idling, running poorly, etc. If the spark is yellow, this is indicated as a weak spark. Strong sparks are shown by a bright blue spark. This particular tutorial was done on a Toro 421 snowblower.