desmoged the I/S cal model about 1 1/2 yrs ago. bought rubber caps to cap the vacuum lines.
today replaced them with "good" ones. four were cracked and broken. also found a vacuum line #11 on carb #3 was capped when i bought the bike, it was leaking like crazy.
bike runs MUCH better now, popping on decel is completely gone.
looks like it's about ready for vacation!! WHOOO HOOOO. can't wait.

P.S. got about 16000 out of e3 on the front. not bad. hope the cobra does as well.