Originally Posted by Nos4r2
I think Andy's right-depending on use. If you usually use it solo then you could probably go up a couple of inches in pitch. 6k RPM is right on the top end of the recommended WOT rpm for a mariner 90 4st.
Quite agree with Matt - I think my manual recommends 5k - 5.5k RPM. If memory serves correct increasing pitch by 2" will drop WOT RPM by 250-400 RPM. This will increase top speed but reduce hole shot.
When I went from a 13.25" x 17" to 13.25 x 19" I got an extra 3-4 kts