Prop sizing help - 28' cruiser

[bazeven2]

Please suggest a prop for me. I'm happy with my current performance, but am buying a stainless steel prop so if I should change, now is the time!

Bayliner 2750 (29' LOA) w/ single Mercruiser 260 & Alpha outdrive. Current prop is 16x14 and spins out at 4200 RPM WOT (listed at 4400-4800 WOT in the manual) and cruises at 3800 RPM @ 22 MPH. I wouldn't mind a bit more top end speed, but don't need it in a boat this size. I can plane very easily with this prop and can bring the rpm's down to 2500 and keep it on plane. Should I stick with another 16x14, prop up to approx 15 pitch or even switch to a 4 blade prop? Suggestions?

Thanks.

Brad Z

 

[j442w30]

Re: Prop sizing help - 28' cruiser

I would recommend dropping down a size in pitch to get your RPM's into the recommended maximum range or else you risk lugging the engine. A four blade would help hole shot but you said the boat planes easily so thats probably not necessary. You did not mention if your boat has them but trim tabs either adjustable or self adjusting would help a boat like yours stay on plane at lower speeds.

 

[bazeven2]

Re: Prop sizing help - 28' cruiser

Thanks. Just to verify - when you say Drop Down a size - do you mean I should go 16x13? What would a Stainless prop do to this # and my recommend RPM's? Using a 16x13 prop, will I lose top end speed as well? How about with a 16x15 - will I lose top end speed there?

Thanks.

Brad Z

 

[Tail_Gunner]

Re: Prop sizing help - 28' cruiser

How old is the boat, does it have a rubber hub or a insert??? If that motor is indeed in tune and your tach is measureing true rpm id go to a 12 pitch but that does not seem right. Take the time to verify your tach, props are expensive and im sure gas it to for that boat....