Dan, any luck? I've worked on these carbs a little. It's the same As on the new 4t. The first thing I do to on the new ones is to install a Jitsie remote fuel screw. I had an '08 4t but did not have to pull the carb or change anything. There is very limited info out there on this carb. I found out a little about them from a 4 wheeler forum as the Yamaha Warrior used the BSR before it went fi.