Exhaust popping noise?

I have a SV650-S 99-02 running a stock exhaust with a drilled baffle (2x4mm holes)
Noticing lately when idle especially, there is alot of splutter, popping or spitting noise coming from the exhaust. Too the point where near buying a new exhaust that noticable.
Is this a exhaust problem or something else?

sounds like the fuel/air mixture is too rich (too much fuel). Is the choke ok?

had the choke out not so long ago, and seems to be ok. Could it be a loss of back pressure from the drilled baffle?
With getting a new aftermarket exhaust how would I adjust this to suit?

the carbs probably need balanced. i had a mate whos bike was doing something similar and thats wot the problem was!

had a feeling it might be that.... curses.
Will get my new exhaust first then get round to that to avoid further costs!

Also noticed other day, took the bike for a good run, and found a empty road and gave it some rag, when got over 100 alot of black smoke came out of the back. Could this be a sympton of running lean/rich or could it be just the fact I never really gun the bike much?

[Binky]

I may be completely wrong here, but is black smoke not when you overfill with engine oil??? Or is it white/blue smoke???

oil when burnt makes a bule/white smoke. This was black as ace of spades, so presuming either settled carbon in exhaust or bike running rich?

thers wot the service manual says about that sorta thing..

hmmm im thinkin worn piston rings there as does tend to use alot of oil lately...
But the smoke never comes out really except for that once :S

the bike wasnt de-restricted recently was it?