John,
Anytime you mess with the carbs, you should re-balance the carbs. There are two on Brents site and there is a link in the tech vault on how to make your own.
I went with Brents cheap on and it works great. You will not believe the difference balanced carbs make not saying it will get rid of the popping on decel.
I actual think it is cool I gave up trying to get rid of it you can but you end up with the flat spot on the low or mid range. I have my screws three turns out and he runs like a raped ape.
