New prop!

[Kng15012]

I’m lookinf to upgrade to stainless prop on my 18 foot open bow, merc 4.3l. I’m not sure on what pitch to go go with. I’m not positive on the current pitch. But I’m looking for all around prop. I do occasionally pull a tube. Update the prop says 231019.

Thanks!

 

[Chris1956]

Looks like a 19" Pitch Michigan Wheel prop. Pretty standard, and probably close to what you want.

Different year MerCruiser outdrives have different gear ratios. Some will run a 19" prop, some a 21" prop and some a 23" prop, on your boat/motor combo, depending on gear ration.

Run your motor up to full RPM (just for a minute) and see what it is, with the current prop. Each 2" in pitch raised or lowered will drop or raise the max RPM by about 600.

 

[porscheguy]

A 19P on a 18? with a 4.3, if the 4.3 has vortec heads and a 1.81 ratio ought to be able to pull stumps.

 

[Kng15012]

Any 19 pitch? I?m kinda confused on the prop sizing. Like the exact numbers.

 

[jimmbo]

Well before you go start buying props it would be nice know what your gear ratio is(it is in the upper gearcase housing decal). what pitch(it is on the prop somewhere) your current prop is, what is the WOT rpm range is for your engine, and what WOT rpm are you getting with the current prop. From there you have a starting point to work from.

I have found that each inch change in pitch, is a 200 rpm shift. Mercury's web site has a prop selector calculator