17 or 21 pitch

[Dutch420]

Hey everyone.
Been looking for a new prop for my boat and today my uncle gave me a stainless quicksilver mirage 21pitch for my boat.. i am taking it to be repaired due to minor damage to the blades..
My boat is a 1992 sr 1900 with the 3liter paper work says 18ft.
Who is running this boat what prop are u running. Currently i have a 17 pitch on it and can over rev pretty damn good. Not a ver good thing !. crusing speed at 3500 rpm is just under half the throttle..

Like i said am curious what other owners of this boat are running for props..
Thanks

[shrew]

What is your current RPM @ WOT?

[Dutch420]

54 to 5500 RPM I know that's way too high because the Max RPM is 42 to 4600 rpm for the 3liter.. trimming it right out you could get it to go a bit higher but I enjoy my boat and don't want to blow it up hence the reason I'm trying to figure out which prop will do it...
I know I could obviously go 19 pitch but I have that damaged stainless 21 sitting there if the boat will run it with no problems and not be "bogging" it down I'd probably invest in getting it fixed if not I'd leave it sitting on the shelf

[shrew]

I would start withe Mercruiser Prop calculator:

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

Each inch of pitch increase will drop the max rpm by approx. 200. A 21P prop would drop you down to around 4700 rpm @ WOT.

Max RPM for a 3.0L Mercruiser should still be 4400-4800.

I would be leary about a damaged prop. damage will effect the cup and pitch regardless of what is stamped on the side. SS props are much more difficult to repair an tune as compared to an aluminum. They can only be tweaked so much and have a tendency to crack.