I run a Merc...I know, I know, please don't stone me to death. Figured I would ask here because you guys are more familiar with flashed out boards and the gains associated.
There is a tune available for the new Merc 4stroke. I have a 250 on a PHX 21. How much of a gain could I expect in performance with a 300hp tune with stock rev limiter @ 6200rpm?