When should you always replace a fouled spark plug instead of cleaning it?

Apr 28, 2011 ... In theory it is possible for it to be your plugs, although if you have bad plugs, usually it won't even start at all. That is just been my ... Sep 9, 2017 ... ... what's causing this for ages and I'm having no luck. I own a 2001 Mx5/Miata and the car is without a doubt running richer than it should (I ... ... 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 24, 2020 ... Having a bit of a problem with carbon fouled spark plugs on my 1955cc engine in a split bus. It had an external oil cooler and never seems to get very hot. Jul 10, 2003 ... Dry black carbon deposits could be an indication of a rich mixture ... More than a quart in 1000 miles is cause for concern in my book. Mar 31, 2010 ... It is possible to foul a spark plug when running it at the proper temp. range, but it isn't very common. One good example would be oil fouling. Feb 10, 2025 ... 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 10, 2012 ... The bike keeps fouling the spark plugs (NGK B6HS). After 2 days of riding (+/-100 miles) they both become carbon fouled, the bike started farting and ... Jan 26, 2009 ... * Carbon fouling: Your spark plug will have a black look, and will ... The cause of this type of foul could be caused by a number of ... Jul 6, 2015 ... What bike? Forget the electronic ignition for now. Get it right first, otherwise you are introducing new variables. Carbon fouling is a result ...