Back to the AIS are you saying they don't even have the plumbing for it on the t/bird now ??
correct. They removed the plumbing starting in '10. Only the pre-order batch sold in mid '09 had the plumbing.
If they did have it on the very first lot of t/birds, that could be why my friends one suffered so badly from the popping
I dunno, but mine is the first one with the plumbing and after the 1700 kit was installed like i said the popping was 95% gone.
Also do you find the 1700 to be not as refined as the 1600 ie more vibration ect
I've heard some say a bit more, but i noticed absolutely no more than before. I've also noted people saying it feels sorta "cruder" or something to that effect. Again i noticed nothing. Possibly the vibration changed a bit and got more low frequency, ad that may account for those opinions from others. Not everyone reacts the same to things like that. To me the bike just sounded a little deeper and the vibes got lower in frequency which is a good thing. But both were rather subtle.