LOL, man I would richen your HSN some more ... mine was doing that and I couldn't believe I had to richen it more, but when I did ... it got better.

That's all you can do man, is keep adjusting it in small increments until it gets better and then you know you are on the right track.

But an OS engine would be cool, but why not try and tune the one you have? On those same lines, I had a air leak, source was fuel tank and was why I had to keep richening things. Once I got that sealed up right, I could actually lean it.