What are the potential downsides of using certain oil additives?

Dec 29, 2005 ... These assume that you're getting carbon or fuel fouling on the plug (which are dry, sooty deposits - if wet, they smell of fuel.) Oil fouling ... Jun 5, 2016 ... I've heard that black carbon on the spark plugs is normally caused by a rich fuel mixture. This can cause the mixture to wash down the cyl. Sep 25, 2006 ... The Boating Forum - What causes a fouled spark plug?? - I have a 2003 Yamaha 130hp. One of the plugs has a wet tip with carbon build 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. Seems to be where it wants to run but plugs still foul (dark black carbon). Jets appear to respond to the lean/rich process and I think they are where they ... Dec 14, 2022 ... I would download ISTA and get the codes that causing the DTM. Post them here. Did you torque the spark plugs when you installed new ones? Or did ... May 31, 2011 ... The carb is new out of the box and it was making all the plugs black carbon. ... dont use the old lead fuel pic s of spark plugs to read ... 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 7, 2016 ... If you ride fast, using a lot of engine speed the hotter spark plugs can cause pre-ignition (pinging), so you'll have to use your own judgment ... Jun 23, 2009 ... Carbon fouling is caused by weak spark, wrong plug heat range, and rich conditions. Essentially, you're burning too cool. Need to heat things up a bit.