I started my bike for 30 seconds to day and a box behind it had a round black soot stain on it I have 9300 miles on a 07 FXDC with V&H slipons and PCIII USB and open air is this normal after it is warmed up no smoke !

 

black smooke dont sound too bad, if it was white or blue could be valve seals!

 

I would agree... though excessive black smoke is not normal... might want to see if you have any codes ....
Charlie D.

 

black smoke is usually a sign of rich on the fuel if only does it shortly at start up wouldn't worry about it check your plugs and see if any wet soot on them if not enjoy the ride..

 

Normal!

 

2 of my Sportsters did that.

 

SOMETIMES, it's a "good" thang !!!!!





A li'l "soot" on the plugs, is way better than a li'l WHITE, with an air cooled.
White = Lean = HEAT, an air cooled's worst "emenee" !!!!

 

Sounds like an over rich idle mixture.
Does it also blow black smoke after warm up?

 

I thought this thread was gonna be about the effects of smoking while starting up your bike and the possible dangers of second hand smoke on your engine.

 

Just runnin' rich on start-up, wouldn't worry unless it blew smoke constantly during riding.