help choosing prop

[sikz3]

Boat is 04 bayliner 4.3l mercruiser alpha one
Although I have never tried to redline it (makes me nervous). I am easily getting 4400 rpms with more throttle to give. I currently am running a 14 1/2 x 19p. I am at roughly 4000' above sea level and getting 45 mph and with three people plus me it comes out of the hole fairly quick. Not really fast but satisfactory. Now to be able to use all the throttle my boat has to offer and gain some mph, what pitch should I go with (21P)?

 

[Bifflefan]

Re: help choosing prop

Why do you want to have Full Throttle?
If you want to go faster then shove the throttle a little harder. Red line is around 5000 i would think but why would you want to do that to your motor?
A 21p will not make the boat any faster except at WOT, and will surely kill your hole shot as its not Great now.

It sounds like you have a really good prop now, why mess that up?

 

[sikz3]

Re: help choosing prop

I would like to get at least 50 without stressing the engine.

 

[dsmmace]

Re: help choosing prop

I don't think you will make 50mph on a aluminum 21P under 4800rpm on that boat/motor combo. Going to a 23P will change holeshot ability.

I would talk with a local prop shop, they normally have used props that you can buy for fairly inexpensive and if that doesn't work they can trade you into another prop.