how to tune up carbs on racing engine

[Taiju Kobayashi <kobao@ccom.sony.co.jp>]

Dear fellow digesters,

I am asking you for your advice on how to tune up carbs of my racing Giulia.
The engine is a 2000 with 13mm cams and 12:1 comp ratio, that means a wild one.

The problems that I currently have are that exhaust manifold gets "red hot"
when idling continued, and also rev comes down very slowly with tremendous
 "backfire" when lift off.  Even though these facts, it does idle at 1000rpm
with
50F11 idle jet. Carbs and carb insulators are new so I suppose no air leaking.

Did I set idle jets too lean and set throttle plates too wide-opened? Or any
problem apart from carbs?

Thank you in advance for your valuable comments on this matter.


Taiju Kobayashi, Tokyo/Japan
'66 GTV (the engine in issue)
'91 75TS
'61 Giulietta SZ (my dad's)