RE: Tuning the OS 46 AX engine
I have two .46-AX's, a .55-AX and a .75-AX. all have ran great right out of the box with very minimal tuning required.
On both .46's I really couldn't tell you how many turns out the low speed screw is. Basically, I just leaned both of them from the factory setting about 1/8-1/4 turn after the first 1-2 tanks of fuel and haven't touched them since.
The .46-AX is almost always an outstanding, user-friendly engine. What you are describing doesn't sound normal. You may want to look for another problem or send it in for repair/replacement.