Prop Recommendation

[Beretta1]

I have a, new to me, 2004 192 Captiva. It has a Mercruiser 5.0 MPI with a 1:62 gear ratio. It came with a Mirage 19p. Best I can tell, 4600-4700 rpm,and, 57 mph. This was with fuel and 2 people. However when a third person is added it takes a longper time to plane out. This boat will be used for family, and, pulling tubes. Can someone help, please? Thanks

 

[Texasmark]

Reducing pitch is how you take a given boat and maintain "hole shot" performance for increases in load. Change in RPM on this site is generally 150 to 200 RPM change per inch pitch change.....diameter may change a few fractions of an inch but that's in the prop design. You usually will have reduced WOT performance, and may have to watch your tach for over revving (above recommended RPM range) when running at WOT and a light load (just back the throttle off if it happens) but improvement in maintaining cruising speed....20-25 mph range also. Additionally pulling water toys will be improved. Don't change from your Mirage as you will introduce new variables. You probably will have to drop to a 17P as props usually change in 2" increments. That's the way I see it.

 

[Beretta1]

The boat was shipped with a Black Max 14.25x21 according to the build sheet. However, someone changed it to the Mirage. Does the 15 1/4 diameter change anything compared to the 14.25. The planing time with 4 aboard is the issue. It takes the 19 Mirage forever to drop over. I would like to go SS in a 4 b design. Thanks

 

[Scott06]

The boat was shipped with a Black Max 14.25x21 according to the build sheet. However, someone changed it to the Mirage. Does the 15 1/4 diameter change anything compared to the 14.25. The planing time with 4 aboard is the issue. It takes the 19 Mirage forever to drop over. I would like to go SS in a 4 b design. Thanks

Frist make sure the engine is in good shape tune up wise plugs, cap rotor, fuel filter, carb is clean etc, ti tming checked set. I would think a 19" would do pretty well on that rig.

Based on your numbers I dont think the suggestion of a 17 mirage is unsound, as that would get your WOT up around 4900-5k. If you want to try a 4 blade that should help holeshot stern lift and planning speed. I have had good luck with the mercury vensura/Offshore and Revolution 4 props. Hard from the keyboard to make a pitch reccomendation between 17" and 19" . Especially the Rev 4 is a big prop with a lot of grip on the water, so I'd think you may want to start lower.

Best bet is to find a prop shop who will let you swap pitches etc and try a few

 

[Texasmark]

Good info from Scott. On the loaner thing, cheapest way to get it right even though you pay more for the exact prop you can find off the shelf elsewhere....obviously.....butttttt look at the big picture...you saved yourself buying 3 or 4 and not necessarily getting what you want.

Remember the dealer has to sell that prop you borrow to someone eventually so they expect you to carefully install it, take the boat out, run your test and stop and take it off and put something else on unless it is what you want and you buy it..just leave it on.