That butterfly is the choke, not the limey choke, the rednek American choke. Your running video sounds like it lacks colds start enrichment, which is consistent with a stuck open choke. It's time to take the air cleaner off and start fiddling with the choke linkage. When cold, it should snap shut when the throttle is opened.

If it is the stuck choke, it should smooth out when the engine warms up.

Last edited by fasteddy; 09/02/13 11:55 PM.
Not responsible for advice not taken...