when engine is not running, throttle won´t open more than 1/3 approx. When engine is running, there is motor which opens thottle when engine wants, you can give order for full throttle, but engine desides how quick it opens it. My engine wouldn´t take rpm and it was little bit :D when I had too open intake, no filter and 3" pipe where afm was. When I choked intake before afm, it started to idle nice and it tooked rev nicely. Stock aircleaner box is not so free flowing, there is approx 3"~76mm pipe where afm is in stock aircleaner box. But I had to make 57mm destriction before afm, to get it work somehow properly. rpm meter won´t be affected by throttle.
I think more of something later.