How do you determine when it's time to replace your spark plugs?

Feb 2, 2019 ... Carbon is relatively conductive and a thick enough coating will cause a voltage loss across the spark plug gap (=weaker spark = more fouling = ... Aug 26, 2015 ... ... ignition event), it could ignite and blow back out the intake. That skipped ignition event could be caused by a fouled/fouling sparkplug, or ... ... spark plug because the exhaust smelled quite rich. The plug (original Bosch WR7 DDC4 with two earth points) was heavily fouled with carbon. I cleaned it up ... Nov 28, 2022 ... I just changed my own spark plugs, and it seems they are Carbon fouled. ... I don't think the condition on these plugs would cause any harm to the ... Nov 11, 2017 ... ... spark plug gets a lot of carbon build-up. Any ideas please because i'm running all sorts of tests and cannot find the cause. Thanks in ... May 31, 2018 ... If the spark plugs have a matte black or grey appearance, it could be carbon fouling — something typically caused by a fuel mixture that is too ... Jun 6, 2011 ... Usually fouling is caused by too rich a mixture or weak spark, afaik. I think getting the right adjustments on the carbs, ensuring the proper amount of spark. A poorly performing fuel pump can cause spark plugs to foul. The plug will have a dusty layer of black carbon deposits. Sep 25, 2015 ... Cylinders 2-5 looked normal. What could cause the end plugs to foul? My thought was those plugs stay cooler, and not hot enough to burn off ... Nov 12, 2020 ... The most common reasons why a lawn mower spark plug fouls are listed below: Air Intake blockage (this could be caused by the choke being left ON ...