NO WAY silverfox, this guy will not loose any low end. the 12mm intake is pure restriction on a v1 engine.
Hey buddy, i do this same exact thing to every minarelli i work on. make the intake 14, then open up the cylender to match it.
You will totally gain low end AND top speed. money back garunteed. milling the head on a minarelli is difficult due to the lip around the edge of the bore.
you were on the right track with boring out your intake. KEEP GOING!