Originally Posted by RIB-Teccie
Yamaha always supplied mid size as standard.
Not on a 30hp, at least not in this country. Up to and including 25hp motors come with a standard prop but that's the largest size coming with a prop. Everything from there up is dealer selected in consultation with the owner based on the boat being fitted.
The range for that engine is 8 to 14" pitch.
I would go with a 13" pitch to start (be sure you have a tach fitted). While its a light boat with a light load they have a surprisingly large wetted surface. Don't spend the extra money on a "performance" prop since you are playing a guessing game to start anyway. Just get a standard prop with 9-7/8" diameter.