[Bill Cuthbertso]

Gary,
The transition ports in my Webers are in the stock position except for the third port which is at 12 o'clock, one millimeter above center. After watching the way the butterflies work, it looks to me like all of the ports are subject to lthe same air flow once the butterflies are off seat. I think the problem with 48's performance in the mid range is a lean condition which is at least partially remedied by a third transition port. As I'm sure you know 48's were developed for racing not curising. Other changes that might help are: reducing the size of the venturies which should increase air velocity ( at the expense of top end), increasing the size of the idle jets, and/or decreasing the size of the air correction jets which should bring the mains in a little sooner. The potential success of these changes would depend on how the carbs are set up before the changes are made. The last alternative is that we may just have to agree to disagree however I do appreciate your comments.
Best regards,
Bill