prop question

[kingofallcookies]

i have a 20ft crownline 5.0 i have a 19 pitch prop now runs 5500 rpm @ wot about 42mph would like to go faster any thoughts
thanks

 

[homerl]

They have told me before that by increasing prop pitch from say 19-21,you will lose take off speed but will gain top end.My boat, I went the other way from a 21-19 because I was slow on the take off but now with the 19 what a difference.

 

[guyjg]

...5.0 i have a 19 pitch prop now runs 5500 rpm @ wot about 42mph...

RPM's too high. Need to be at 4800 max. Try a 4 blade 23-24 pitch for hole shot speed and top end.

 

[ayleeuss]

i am assuming you have a 1.62 gear ratio. if so that prop has about 31% slip.
something dont add up here. U sure your tach is acurate?

http://www.rbbi.com/folders/prop/propcalc.htm

 

[j cat]

your boat load must be very low . with this engine your over the recommended WOT.

how well does it get up on plane from DIW ? going to a 21inch should drop the RPM down to 400-500rpm. I would not operate over 5000rpm at any time ..too high ..