they are the shiny screws in the front. Will slap a magnet on the intake tonight.
So with the 23 mirage plus it turns 4600 rpm. If in fact it is the magnum it should run 4800 rpm I believe. I have a 21 mirage, 24 4 blade which I can try. I think the 21 may be too small and unsure how going from a 3 blade to 4 blade affects rpm.