Crazzy prop

[scooter4n]

I have 18' chaparral bow rider with 3.0 Mercruiser I just got.
It has aluminum prop with crazzzy size: 15 1/2 x 41 is this possible???
I get 4000PRM at WOT doing 35mi/h GPS with 4 ppl in boat.

 

[WillyBWright]

Re: Crazzy prop

No that's not possible. 14-1/2 x 21 would sound more in the ballpark. I'd think a 17p or 19p might be more appropriate to get the RPMs up, 4000 is too low.

 

[scooter4n]

Re: Crazzy prop

I want to upgrade. I want to go with SS prop. what size should I go with. I usually have 4 or more people in the boat. Im not looking for speed, I want more just at take off, but little speed wont's heart too, but more at the buttome end.
Please recommend.
Thanks
P.S. I'll have picture of the numbers from the prep posted later.

 

[scooter4n]

Re: Crazzy prop

I'm thinking to get:
Stainless 4 blade 14x20
what you all think?
(18' bowrider 1990 3.0 Mercruiser)

Thanks

 

[tommays]

Re: Crazzy prop

It really depends on your goal mine was to get better LOW speed performance and the best fuel economy in the 25 MPH range on long trips


If water skiing was what you want to do it would be the wrong pick



I run at 14 X20 4 blade ALU prop on a 19' 3.0 powered boat

It is the BIGGEST prop i would even consider and the extra bite of and SS one might be a bit much and result in to low of a WOT which should be in the 4600 to 4800 RPM range






Tommays

 

[scooter4n]

Re: Crazzy prop

I don't do any water sports.
mostly cursing, but I want to go fast from 0 and up. maybe top speed around 40mi/h and around 4500RPM
what should I go with then? Defiantly SS.

 

[tommays]

Re: Crazzy prop

Really need to know what is on there NOW as if it is a 21"


The 4 blade is going to give away top speed in exchange for low speed performance


It is hard to tell from here if it is even running good recent service ect



Tommays

 

[scooter4n]

Re: Crazzy prop

now I have 15 1/2 by and there is 21 stamped over 19, so hard to tell is it is 19 or 21, but looking at the low rpm's at WOT I bet this is 21.
I don't really care about top speed, I like more just at the low end, and mid range, and be able to get to 40 mi/h as well.

 

[scooter4n]

Re: Crazzy prop

I'm stuck. I went and read all posts around from last 50 pages. Got tons of feedback. Good stuff.
Stuck between:
SS 14x20p 4 blade
and
SS 17x19p 3 blade
I was just reading this post> http://forums.iboats.com/showthread.php?t=214503
Just don't know.

 

[scooter4n]

Re: Crazzy prop

any1??

 

[Crownie2]

Re: Crazzy prop

I guess you are just going to have to try one or the other. Know any dealers who will allow a test?

Lot's of good info in those posts - as you can see there are those who prefer 4 blades on their boats and those who don't. I think for your boat I am in the three blade camp. I guess you will have to try them and decide for yourself...

Bob