2008 1900 SR3 correct Prop

[Mexipino]

So our 1900 SR3 has a High Five 21”pitch on it and it is fairly slow out of the whole. Of course. I cannot find what the original prop would have been for this boat. I looked it up on Mercruiser’s website and they pretty much suggest using a 17 or 18” prop. That is a big jump to me.

2008 Maxum 1900 SR3 305MPI our drive is the 1.6 model.

Can you all tell me what u use on ur boats and how well they perform?

Thanks
Donnie

[mmwjr]

What is the boats WOT? Should be 4400-4800 rpm.

I would think this package came with a 19” pitch 3 blade prop. A stainless steel 5 blade 21” pitch puts a fair load on the engine.

Not sure what you mean by the drive being a 1.6, do you mean Alpha 1 Gen 2 with a 1.6:1 gear ratio?

[Phillbo]

Call these guys at Hill Marine. They are the experts and will set you up... But, you do need to know your current WOT RPM's as suggested above. That is your baseline.

https://www.hillmarine.com/Default.a...BoCqgAQAvD_BwE

[Mexipino]

Thanks Phillbo!

[Mexipino]

It is the Alph1 Gen 2 with the 1.6:1 ratio.

I believe it tops out at 4200 and 45ish MPH

I am hoping for pop out of the hole.

Thinking about 14” 4 blade...

Thanks for the response!

[shrew]

https://www.mercurymarine.com/en/us/...or/#!/step-one

[jrsick]

A 19 ft boat with a 5.0 is going to have a lot of pop out of the hole. The 21P 5 blade prop you're running now is roughly equivalent to a 23P for rpm calculations. A 19P 3 blade prop will give you a significant improvement in hole shot over what you have now, and will get you on plane quickly. You would still have a 50+ mph top end.

[Mexipino]

I did this calculator. and it told me I needed to use a three or four blade 17 pitch. That is significantly different than what I have and I got a lot of mixed messages online. That’s why I reached out to this forum.
Thanks for responding.

[Mexipino]

Thanks!!!