As stated there are several unknown factors which need to be known to make a correct selection. Here's my take on your boat:
- the prop is in an aperture so the repower
was done with a 2.21:1 reduction ratio so as to require the smallest prop
With this ratio the ideal prop is a 14.7 X 7.8 X 3, but probably a 14 X 8.5 X 3 was fitted if it can fit in the aperture with adequate tip clearance (approx. 15%).
If that's too big go to a 13 X 8.5 X 3, and if that's too big you will have to continue down in diameter and up in pitch
about an inch at a time on each.
Once below 13 " diameter, efficiency will begin to suffer as blade area gets too small. Your engine
will use a right hand prop.