Whew, I'm glad the units correction was made. A .040 inch clearance would have been a disaster. All dimensions in the Saito manual are in mm.

As a point of reference, my 72 wouldn't idle until I turned the idle screw in two full turns. I fine tuned from there. Do as snownskate69 said and gradually screw the idle screw in until it bottoms out. If the engine still fails to run, you have a defective engine. If it is defective, send the entire engine back to Horizon. I wouldn't bother with removing the carb or checking the timing. That's why you bought the three year warranty!