propeler pitch which one

[dave3235]

Hi all

Just wondering if anyone runs a Honwave 3.5 with a 20hp 2stroke 13 pitch.I was thinking of uping the pitch to may be 14 or 15 and what sort of speeds can be obtained from these changes.I normaly have 2 of us on board.At present I am getting around 23mph, the weight is around 30 stone on board and seems to rev freely not under load.Any body running or have run theirs with these pitch props.

Sorry forgot to say aluminium prop

[beerbelly]

the prop pitch is determined by the revs at wide open throttle not easy without a rev counter basically you use a prop pitch that will allow the engine to top out at or just below the engines max safe rev limit .things to consider upping the pitch is the boat may struggle to get upon the plane and not manage to pull its top rev ceiling /top speed if its over propped . if you have it under propped it will fly of the mark but either hit the rev limiter or go into meltdown from over revving. I had a 21 pitch prop on my fletcher with mercury 75 when I got it it maxed out at about 40 but wouldn't pull a skier on two ski,s out of the water we dropped it down to the recommended 17 pitch and it then pulled the ski,er out no bother and top speed went up to 45

[dave3235]

Thanks for your input,I understand what your saying but am hoping somone has tested a similar set up just trying to short cut the tach and trial and error processe

[dave3235]

Looks like im gonna have to spend some extra cash

[Landlockedpirate]

Have you tried the Mercury Prop Selector ? It has a limited number of other engines in there and you can usually get a decent approximation of your own set up to get results. Just put in the nearest details available to your boat and engine package.

Guessing a few of your figures and using a Rib as a bench mark (No Sibs on selector) it does suggest a a higher pitch prop than your are currently running.

Prop Selector | Mercury Marine