Prop question for my merc.

[plio7]

i just upgraded my boat a little, and bought a 1980 vanguard with a 1980 70hp merc. i have a funny feeling that the prop is wrong, i'm only 14' long with good lines and i'm just bearly squeeking past 30mph. also the boat isnt going much past 4000 rpms. will a prop change this, is it possible the guy has a wrong prop on there?

thanks very muh in advance for any help

 

[Firestar]

Re: Prop question for my merc.

We need to know the prop pitch. Sounds like you might have to much pitch.