Bumblebee stuttering

[jackt]

I have a 97 bumblebee always ran great. but lately it (stutters) when I first start for a few minutes then goes away. Only when it first stats, And starts very easy very little choke. Only does the first time I start in AM then not again all day.
It has stock exhaust and its very quite just kind of phoot phoot (that's the beast I can describe sound).
Any ideas I have checked the valve clearance and timing and its right on.
I have ran Sea Foam and Lucas injection cleaner thru it.

Thanks for your suggestions
jack

[KRC]

I'd check all the vacuum lines going between the carbs, when i first bought my 03 I thought it was amazing since it started with zero choke even when it was 40 F out... then I found 3 of the lines split wide open and the rest cracking.