I was having problems with stalling and rough starts with my LX-150 and after finding this on Modern Vespa I just wanted to repost it for any other newbies like myself who might have encountered this problem.
Totally did the trick!
ET/GT/LX: Hard Starting, Rough Idle, or Stalling
You don't find this kinda stuff in the owners manual.
This forum rocks, thanks!
Cheers.