At sea level, yes do put a .1 shim in with 30% fuel.

Yes, it's a high end novarossi motor built to Mugen specs (what differences it has between the Mugen X12 and Novarossi NS12, I dunno.)

BTW...very good motor (even with standard plug). I can keep up with some very good modded engines on the back straight of my home track (200+ ft straight)