TR4A SU Carb Problem

[Jim Jones <jonesj1@toad.net>]

All,
Adjusted my SU H6 carbs on the TR4A.  In adjusting mixture, I could not get
the front carb to do anything.  Lifting the piston had no effect.
Adjusting the jet seat had no effect.  Appeared as though there was gas
coming out the seat, but it runs very rough when cold and somewhat rough
even when hot.  My guess is that it has to do with the float or the
butterfly valve.  Which one is most likely and what should I look for?

Jim 67TR4AIRS