[WFBowen]

Josh:
Does it seem like an over-rich condition or do you think it's fuel starvation during these times?
If you think it's starvation, I'd check fuel pump (actual delivery under this specific condition); float levels & accel. pump gaskets.
If you sense over-rich, plugs/heat range; float needle valves; proper jetting of Webers.Just guesses, but maybe it'll open some new doors.
Sleep easy - at least it starts up!
Bill.