[subxero]

can't really help you out any more with out some decent info about how bike is running.

go for a ride, get bike to operating temps. Stop, let bike idle for few seconds until idle is steady then crack the throttle quickly then close it quickly, watch rpm, do they dive or hang high?

Go for a cruise on a nice flat stretch of road with out any stops where you can maintain 45ish-55ish mph and not impede traffic or put yourself in danger and in whatever gear get rpms in 7k range give or take with minimal throttle no more than 1/4 open and then proceed to accelerate until 10k rpm under different throttle inputs. 1/4 open, 1/2 3/4 open & pay close attention to how bike feels. Then repeat exact same thing with choke on full, how does the bike behave differently with the choke on full. (note using choke to trouble shoot main jet/WOT is not overly useful)

for WOT, put in the 108 main jet and get bike to operating temp and do some WOT runs is it better or worse than the 106?

good answers to those questions might help.

And I still think you need to check for an exhaust leak and double check all your hoses to make sure everything is in the right place and secure which is probably cause for popping with closed throttle/decel......like I already said once.