need help with prop and rpm`s

[redlabel1]

good evening new to the site. i have done many searches and can`t quite find the answers i am looking for. I have a new to me used boat it is a 1860 crestliner with a Bf75 on it.I use it for bowfishing so it has some added weight from the front deck and back deck, generator, batteries and so on. My first question is on it now it has a 13 3/4 x15pitch prop and i can only get 3500 to 3800 rpm`s and 29mph (gps)out of it wide open and if i try to trim it up the boat jumps up and down sometimes at higher speeds so i have to run it with the motor trimmed all the way down.What prop would you recomend because i have to get a new one as i hit a log and broke 2 blades off the current one.And 2nd question is shouldn`t it be running higher rps wide open? thanks for any and all help

 

[pvanv]

Re: need help with prop and rpm`s

This question is probably best answered in the prop forum. But the deal is that less pitch will equal more RPM. On a planing boat, maybe 500 RPM per inch of pitch. So you can likely go down to about 12 pitch, and expect to approach 5300 RPM WOT, plus get better hole shot. Not sure of the Factory-recommended WOT RPM for that motor, but that data should be in your owner's manual.

 

[Sea Rider]

Re: need help with prop and rpm`s

You could try propulse props for your engine brand, are pitch adjustable in seconds and blades replaceable if any of them breaks, are well priced interesting option.

Happy Boating