First of all I have to laugh my ***** off because I just went through the same thing with my OS .46FX engine. I went through 2 tanks before I could even get the thing to contunuosly run without the glow plug connected.

Yeasterday I finally was able to fly with it, and the way I tuned it was just pot luck. The instructions really don't help because of weather temps , prop size ,% of fuel being used , etc.

So I went as lean as I could and back to rich slowly until the engine ran in idle position and when tilting the plane up and down . Man was it cold out but I was determined. My instructions say optimum setting is 1 1/2 to 2 1/2 turns on needle . I have mine set at one turn and it doesn't over heat. [X(]

The moral of the story is burn the direction because they can't and don't apply for every application in which the engine is being used.

I hope this helps , thats a big engine you have .............break it's back