2006 busa running rich with Two brothers racing slip-ons


I have been a long time lurker on this website but have finally joined the Hayabusa.org family! so first and foremost, thank you all for all the help and advise you guys have given me about my bike... even though you didn't know it!:laugh:

Anyways lets get to the point, I have a 2006 hayabusa that I bought last year. I bought the Two brothers racing M-5 slip-ons and have had them on for about 4k miles now. I have recently noticed some hesitation in lower RPMs, a slight surge at about 50MPH, and it will now take about 5 seconds to start up. My first thought was that these slip-ons are causing my bike to run rich so I checked the spark plugs but they looked perfect. I upped the idle a little bit because it was falling to 1000 RPM and it made the bike seem to run better for a while. One month later (this month) it started to feel out of whack again and now it is smelling more rich when ridding. I did a throttle body sync (bike now has 9k miles on it) thinking maybe this would be my issue but the meter indicated they were not that far off. I checked the spark plugs again and they are LOADED with gas now. I was told that just putting these slip-ons on there would not cause an A/F problem. But it seems that was wrong. my buddies whom I ride with told me from day one my bike was smelling way rich but I dismissed it because a bike will always smell richer after doing cans and since the installation my bike actually gained 5MPG! So what gives???? anybody have any ideas? How can I ride around for 4k miles with out my plugs fouling then within a months time my plugs are bathing in gas? Again the only mod to this bike is just the slip-ons everything else is stock. Should I get a power commander or Juicebox pro and be done with it? Or might there be a more serious problem?