Hi Carl,
My current set-up is mains 135
air correctors 170
emulsion tubes F15.
Also running 40 DCOE's. (40 DCOE 18)
My engine is not stock. Intensively modified PBS head with bigger valves, a more radical cam, lot of shaving, hi-comp pistons.
Since the car is not a driver yet, I can only say the engine seems to be running strong, with only a tendency of idling too fast... That's also where I am actually.
Transition between idle and acceleration is one of the challenge of these carbs and there is no easy answer. In theory your F11 emulsion tubes are barely enough for a 1300cc. That maybe the problem, but I doubt it. I think it would show only at the limit, but I'm no expert.
Some carb guru can jump in, but in theory, at idle, fuel is entering by the idle mixture screw. Under acceleration , it's coming first by the idle mixture screw, the progression holes and finaly also by the pump jets. Then, when normal speed is reached, the main jets are regulating the quantity of fuel.
The first question would be, is this a transition problem or is this just because there is not enough fuel in the normal running phase?
Timing may also be part of the equation. Have you tried loosening the distributor bolt then turning the distributor while the engine is in the running phase? Also looking into the carbs, notice the fuel delivery related to the different phases. Does it seems there a fuel cut-off at one stage?
In my case, I worked weeks to discover I had a weak acceleraton pump rod spring, causing one carb's throttle to remain barely open, then leading to backfires (or spitting).
Ulix, tell us more about the wideband O2 gauge...
Daniel Forest