Wow!

This is getting to be such a common complaint, that I no longer feel lonely about it.

I and many others have also been fighting a 1.35 with the very same symptoms. I think it was Bob_n, that adapted a OS 7D carb to his, and all the problems went away for good. I personally really hate to think one should have to buy a $65 carb from another manufacture, to end up with a great running Moki. The most irritating thing is, how the dist. brags up the Moki smoothness and transition at all throttle speeds. "The Throttle transition characteristics are without equal in any other model engine". Maybe I just take that quote the wrong way

All that aside, now on gallon 7, mine is no longer dieing in the air, and seems to be showing signs of improvement with every tank I run through it. It seems to be more and more tolerant of the overly rich midrange condition as it gets more broken in.
The fact that this thing runs good till it gets up airspeed, sounds like that very large Moki air intake could be the cause of the problem. In order for the engine to go rich, there must be a vacuum forming over that air intake. I've also noticed a lot of side slop in the carb barrel. When that thing moves at will, there must be a very uneven fuel flow through the low speed groove.
It just seems like a very crude carb setup to me.

Hate to sound so negative, but this engine has been a very unpleasant experience. I was just expecting so much more. Live and learn I guess.

Kevin