So, I've got the exhaust pipe headed outside to the mufler, and the the exit points straight down (6 o'clock) Over time, soot was accumulating on the side of the wall 4" away, so I stuck a sheet of sheet metal to divert the exhaust plume away from the building.
Today, I noticed that there was (after about 80 hours use) about 1/3" of an inch of soft, dry fluffy carbon soot built up on the sheet metal. I get a bigt of smoke right at startup, and if I ramp up the load slowly, the exhaust stays pretty clear.
So I have 2 questions.
1) is soft, dry, fluffy carbon normal
2) would it be building up inside the pipe and muffler ?