How can you prepare your vehicle for an emissions test?

... 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 ... Clearing a Fouled Spark Plug. Featuring Bob Nardiello. Subscriber question: "What is the most likely cause of a bad magneto check during run-up (too large a ... Jan 29, 2014 ... No more fouling of number 2 and the engine runs better then it ever did. Still puzzled about why only one spark plug fouled. Check out the carb. 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 ... The causes for such a buildup include a heavy carburetor float, a leaky injector or carburetor needle valve, malfunctioning of the spark plug wires, or ... 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 ... Dec 31, 2020 ... Spark plugs fouled with black residue, often greasy in quality. After cleaning off plugs, she starts/runs well, for a few more weeks, then ... May 23, 2022 ... ... spark plugs, they foul badly with black carbon after only 20 ... fouling, I was hoping to rule out the original Strombergs causing the issue. Aug 20, 2006 ... What would cause the front cylinder spark plugs to foul heavily with carbon on my 2002 VTX 1800C? The rear cylinder plugs were ok. Jul 3, 2003 ... I have a recuring problem with #1 plug (front of engine) fouling with carbon from what one would describe as an over rich fuel mix.