Try going back to a single carburetor, or at least block off one carb on the dual manifold and see how it runs. It's beginning to look like that eye candy carburetor system is the culprit. Unless you're planning to run wide open throttle at top engine speed all the time, the duals are as useless as a screen door in a submarine!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!