Motorcycle Repair: un used fuel? popping on the end can, bandit 650s, suzuki bandit

Question
hi there I recently purchased a suzuki bandit 650s I had a titanium race end can it seems to pop at the end of the exhaust I am a mechanic but I usually specialize in 2stroke engines tuning them porting. Also because it is EFI 4stroke how can i tweak it is there a clip on chip ?

your knowledge would be greatly appreciated

Answer
I don't really know these bikes (read my profile) but if the exhaust pops on the overrun (as you shut off the gas) then a muffler with better airflow can cause some popping as the revs come down.  For mapping differently you can try a power commander of such device to get different performance levels.  Good luck,  Jan