black smoke up high
 

Yesterday I reved my bike up. And I saw black smoke shoot our the tail pipe I can keep doing this and it will do it only does it when it in very high in the rpm. I recently bought the bike and don't remembeor it doing this when I got it but I have to admit im not one to be just revind the piss out my motor for giggles. I rode the bike probably about 250 miles yesterday and did not notice anything unusual. Backround on my bike it has a two brother exhaust and mid pipe bit other then that stock as far as I know. It has just about 18500 miles on it. Does this sound as it may be the fuel pressure regulator that is on its way out pr possibly just cause the plugs are due to get the changed?

its prolly just running a little rich black smoke is just a little fuel commin out that wasnt burnt. i was riddin my buddys bike and i was on his and he opened mine up and i noticed at little black smoke. then i got back on mine and noticed his bike did it he also has a pipe like me and my friends whos is stock doesnt do it so it might have somethin to do with the pipe on it being less restricted