What does black smoke from the exhaust typically signify?

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 ... 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 ... It has a Crane HI-6 ignition and MSD Dist." Well, if it's fouling plugs, (assuming the fouling is from gasoline and not oil, such as caused by bad rings or ... Apr 13, 2023 ... The unburnt carbon will be deposited on the spark plug, causing carbon build-up. ... Every car has an oxygen sensor, which monitors the air and ... Feb 8, 2023 ... 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 5, 2024 ... Since all four plugs are fouled, I would lean towards oil. You may have lost a seal on the turbo, or the new PCV diaphragm may be faulty. Carbon fouling is an indication of a rich air-fuel mixture, weak ignition, or improper heat range (too cold). Carbon deposits are conductive and can create a ... Apr 29, 2012 ... Thanks Jim. I'll check the air control cable. That sounds like a likely cause. There seemed to be good tension at the lever but of course that ... Jul 8, 2010 ... Carbon fouling - Dry, black sooty deposits leading to misfire and weak spark. Caused by an over-rich fuel/air mixture, faulty choke operation or blocked air ... Apr 8, 2004 ... the plugs are dry black "coated" the engine begins to miss, can take spark plug wires off and no noticable change in idle acceleceraton. the egr ...