Honda BF15 Prop Advice

[Collwyn]

Does anybody have any experience of prop pitch with a similar set-up to:

Boat - Suzumar 360 AL
Engine - Honda BF15
Prop - 9 1/2" x 8 5/8"

Currently I get:

1 adult - 16 kts at 6,000 rpm
2 adults - 15 kts at 6,000 rpm

The boat seems to accelerate very quickly and gets on the plane very easily.

I cruise roughly about 12 kts at about 4,500 rpm I'd say.

I would like a faster cruising speed at 3/4 throttle if possible.

So could I go up to Honda's 9 1/2 x 9 1/2 or even 9 1/4 x 10?

At about £90 its a lot just to 'take a chance' on but if anyone has any real world experience with a similar set up, advice and thoughts would be greatly appreciated!

Thanks in advance.