hey guys I recently put a HD sporty competition pipe on my bike and have a quick question... my bike shoots black smoke out of the pipe when i accelerate but when i coast with the clutch out ( like when slowing down for a stoplight) it backfires and the pipe is bluing just a little am iI running too rich or too lean? and should I make a mixture adjustment? she runs excellent and I dont wanna mess it up to where it fouls plugs constantly or sounds like an AK-47 lol BTW im running stock jets and the mixture is at just about 2 turns.

Really? Thats interesting, didnt know that it will backfire if its too rich  but whats causing the bluing? thanks, I just learned something new

Yup,... lot's of rich popping around here...
I live in an unusual place...(a valley 2600ft up)... every decent ride goes up from here... to 4,000 up to 9,000ft...
Elevation, makes air thinner, and makes your bike rich...
I start popping between 5k and 7k... (If I adjust for that, I'll be too lean in town)...
So,... rich pops are very common...
Plus,.. there are lots of people here that over jet their bikes, thinking bigger jets will make them faster...
(It don't,... but, it sure makes for backfires)...

Your pipe is blueing from being too rich... (excess fuel is igniting in the pipe, creating heat)...lean conditions don't cause blueing,.. heat does... heat comes from a poor running engine, rich or lean... or, just plain ol' heat from riding in hot weather, or wooping the pants out of your engine... (chrome goes yellow, to brown, to blue, to black, as heat increases)... I know, 'cause mine is a rainbow...
Mine is blue/black... partly from lots of mountain rides... mostly from a leaky petcock that was broke when I bought the bike... and I never cleaned it off...
I leave the blue on there... (looks bada$$)... (plus, I don't want to fight that battle)...
...

If you want to look like a rider... leave the blueing on there...
If you want butt-jewelry... buy some Blue Job, and rub, rub, rub....

PS...(if you want a blue pipe, just for effect... just sit and idle for 10 or 15 minutes)...
That otter doit....  ... (it's all about heat)...

Many is the amateur tuner,... that has spent too much time adjusting the idle, and seen his pipe blue... and then went bigger on the jets based on the blueing...
It don't work like that... Just idling too long will blue the pipe...
Don't adjust jetting based on pipe color... that don't work...
Adjust for performance... blue be d@mned...