I think I have a problem - anyone want to listen to it?

[Hermanji]

Thanks for the heads up about the exhaust studs.

I've tried varying exhaust flow and blocking 'leak' with rags - no change.

But, I do like your idea about carb balancing. I've just been reading about how imbalanced carbs can cause engine vibration. This seems like a good description of my symptoms. I've also started having difficulty getting the choke right - I'm looking into it.