Jerry,
Mine likes to do the loud startup pop ocassionally too. It always happens if I even touch the throttle when starting it. It scares the crap out of people, makes them jump really high and girls squeal. Hee hee. Sometimes I do it on purpose for poops and grins. I also am one of those people that rarely turns off my petcock.
What condition is your airbox/snorkles?
Definetly up your mains a bit too and get a lot more giddy up for a few $$.
If you are running 4 turns out already, you may want to try 45 pilots and turn the secrews all the way back in and start from there.
You will never get rid of all the popping, but you can decrease it a lot.
Mine pops on decel slightly still, but it doesn't bother me as long and it's not like a machine gun.
