AVS2 650 Secondary Bog

I've had it for a couple of years but only tried it on another engine without success. Yeah, after I tightened the door and it had no effect I figured that was not the solution. The carb runs great on the primaries, very snappy compared to the QF I was using. We'll get to the bottom of this!!
I'm not familiar with those carburetors, as I've never used one, so I'm sorry I'm not much more use. I assume it ran well with the carburetor you removed?