So here's what I have going on: variated vespa bravo did a malossi gears and swapped for a treats lightened clutch bell. The bell rubs up against where the clutch shoes sit and is hard to start so I fixed that by shimming out and it Freed up and spins freely but, now I have where if it hits speeds it acts like I'm pulling on the decomp then dies off. Ive tried everything from lapping the valve seat to loosening up the tension on the belt still does the same thing. But once its swapped for a single speed transmission it operates normal. What in the wild world is even going on?