Weber transition port sizes

[911pcars]

On Weber 40 IDA/IDT etc., does anyone have any idea the factory dimensions of the fixed transition ports near the edge of each throttle plate? I suspect my recently acquired set has been drilled/enlarged as I'm unable to lean the mixture off idle > about 3800 rpm using different idle, main, air correction jets and float setting.

I can adjust the mixture before and after the above range (confirmed with A/F gauge).

Thanks,
Sherwood

[1QuickS]

From bottom to top:

IDA, IDAP & IDS:

• 0.80
• 1.10
• 1.35

IDT (not IDTP):

• 1.00
• 1.10
• 1.35

IDTP:

• 0.70
• 1.30
• 1.20

[911pcars]

Whoa. Thanks for the info Paul. Will try to confirm.

Much appreciated
Sherwood