Thinking further . . .
Are your accelerator pumps giving a little shot when the throttle advances from idle? You should be able to see it when you look down intro the throttle bores from above. It should be an even, fine mist.
"For every complex problem there is an answer that is clear, simple, and wrong." (Henry Louis Mencken)
2005 X2, Viper Red, MCX, Acme 1285, PPass, rear 750 sacs, KGB, IBS
(previous) 2001 X5, 1991 TriStar 190