[JerryHawk250]

Originally Posted by Megadan

I was also having the same thought as paulsstag. Swapping carbs with the same result tells me it isn't the carbs. However, the intake to the head can be the culprit via a vacuum leak. The O ring that seals the intake to the head may be pinched or missing, or the flange was bolted down too heavily and warped the flange (it's soft aluminum), or the rubber may have a rip in it somewhere.

^^^This is what I was thinking. ^^^ Air leak