I had the same with mine... let me guess... when engine-braking between 5-3k revs you get a few barbles, then 'pop' 'pop' 'pop' 'BANG!'
Sounds and looks great but isn't too good for the bike in the long term. (Although was great with my twin cans seeing a blue flame alternate between each can a few times, followed by a foot long yellow flame and a 'crack'
I went to my nearest bike place that do Dyno adjustment (Rhencullen) and for £70 they could adjust the air/fuel mixture throughout the rev range by 10%. (I think they called it a 'Yoshi' adjustment? Could be wrong...)
This put the air/fuel mix into acceptable allowances where it now very rarely pops, and on odd occasions bangs (one in 10 journeys maybe?).
I also had a dyno print-out with this too.
It was either that... for £400 for a spot on Power-Commander including the set-up, I'm more than happy with it as it is
