Lean idle. Rich cruise.
Didn’t you dyno your engine? If so was it locked out then?
It would be rare that your engine would hate a curve.
In fact, do you mind posting your best curve you’ve found? Whatever was the best of the curves?
Edit: if you have 4 open emulsion holes it’s probably too much.
Edit II: what size is your carb and what size is the main air bleed?
Dyno'd it when built. Engine dyno. Locked.
The only curve that even was close was 10 degree bushing with two light springs. 25 initial, all in by 2500(35) It hated that the least. I tried every spring combo possible. Went all the way to 2 heavy springs. 25 degrees initial and all in (35), at 4150RPM. Also every friggin setup was rich cruising to the local "spot".
as stated earlier my carb is the XP Ultra 850.
MAB is 34. I went down to 30 and it was richer, just like I thought.
Emulsions are brass, all open. Never measured them but they appear to all be the same size. Seems ridiculous to me. Back in the day we didn't see that on the old 750 DP, or even the old Dominator 750. Which I thought were EASILY tuned.
And forTT5.9, my wideband data logger is my nephew with a cell phone.
As for checking each mod, I use a Draggy. All passes were close in temperature and RH. Really didn't need it though. 35 locked is dramatically different than all 9 curves(spring combo's) I tried.
I may be a little carb stupid, but I've been at this game a loooong time. Just trying to get it as perfect as I can. Been running around rich at cruise for a few years and just figured what the hell, it's great at Idle, great at WOT no big deal. Now.....I'm irritated as hell that I cannot get it to 100%.
Personally, I think I'm on the main jet at cruise RPM. 80's up front, 86 in the back. 2 4.5 P valves. idles 10 inches vacuum at 1150 RPM.
Look guys, I know this is rambling but I really would like to get things a bit better. I do plenty of cruising around, sometimes for nice long rides. If it was a total drag car, I would leave it alone.