Aaron,
The DCOE idle/progre
Aaron,
The DCOE idle/progression circuits are substantially different, by design than the IF3C carbs, as used on the BBs. On the DCOE carbs, it is possible to jet the idle mixture and transition mixture differently.
Typical DCOE idle jet notation: 45F6
The 45 number is the idle jet size.
The F6 is the transition jet size.
The idle jet doee have an effect of the transition mixture, though the transition hole (F6) has little effect on the idle mixture. This area of jetting takes a fair amount of patience and experience to get right.
I prefer to dial the idle mixture in first....
Say we choose a 55F11. We find that the idle mixture screw is in the middle of the range, and the mixture strength is "correct". However, we're too rich on transition. I can recall from memory which way the jetting changes, but for example only your new idle jet will be 55F8. Pierce will know which way the second number (F8,11, etc) goes to lean the transition.
As to the leakage past the enrichment circuit...Typical I guess, though two solutions come to mind.
1-Dissassemble carbs and inspect the seats where the enrichment pistons sit. Relap seats and/or pistons for a better seal.
2-Speak with Pierce about using a block-off plate to remove the entire enrichment circuit. I can't remember the details of this minor mod...though I did this on many Alfa engines 15 years ago.
Regards,
David
