Mikuni has changed the VM manual materially as have the the carbs been changed to deliver 4 stroke fuel differently than the 2 stroke carbs that many of us are familiar with...
I'm attaching a .pdf copy of the manual here below and it is available with a Google search as [vmmanual.pdf] too...
Many page changes but especially call attention to [Manual pages 3-4 & 7] - on page 3 come to understand section 3.2 and all of page 4 - on page 7 a language confusion still exists on figure 11 [X axis] [PS per Cylinder] is German/English for [HP per cylinder]... Mark up your copy...
Print the manual out to see the graphic detail that is most useful but not apparent viewing on a PDF Reader... Not so clear is the shape of the three different kinds of main jets - look the jets up in a Mikuni Catalog to see photos of these parts
This Carb and Manual require considerable study to get the nuances - you can be doing that while building the airframe)-;..
Put .pdf Page 20 on the front of your printed manual? The first order of understanding - is the list of parts and their relationship to the slide opening... It is a fact that too large an aperture (I've always called that a Venturi) will cause a single cylinder to go to full power at about half a slide opening - think about the effect that has on the page 20 drawing relationships...