So I've looking for a backup/secondary prop for my deck boat. Happy with the current performance of the stock 14.25x21p merc prop, but something with more stern lift would be nice.
The boat is an interesting challenge. It is somewhat of a barge to get moving, but once it is up and running the boat moves! (essentially a tri-hull with minimal deadrise.) Because of the heavy back end, I rarely ever trim up at all, it is almost always all the way down. Only at full out WOT can I start to move it up, and even then, it will start porpoising fairly quickly. With the hull design and aft weight, the boat does not like any speed between 10-20 at all, so most of my boat time is either idle speed or low 20's.
1) Performance issue you are trying to correct.
Second prop and better midrange manners.
2/3) Current prop manufacturer, model, aluminum or stainless as a minimum.
Mercruiser 14.25x21p aluminum 3 blade
4) Wide open throttle RPM and speed with an average load (very helpful)
4800+ RPM and 49-50 mph.
5) Engine/drive make, model, year, and HP
Mercruiser 4.3l/4 bbl
6) Boat make model, year, length and weight
1994 Kayot Corso, 18', ~2500lb
So I'm thinking most likely a 4 blade, probably SS. Pitch is a question, considering I'm at or above the top of the rpm range already. Thoughts?
The boat is an interesting challenge. It is somewhat of a barge to get moving, but once it is up and running the boat moves! (essentially a tri-hull with minimal deadrise.) Because of the heavy back end, I rarely ever trim up at all, it is almost always all the way down. Only at full out WOT can I start to move it up, and even then, it will start porpoising fairly quickly. With the hull design and aft weight, the boat does not like any speed between 10-20 at all, so most of my boat time is either idle speed or low 20's.
1) Performance issue you are trying to correct.
Second prop and better midrange manners.
2/3) Current prop manufacturer, model, aluminum or stainless as a minimum.
Mercruiser 14.25x21p aluminum 3 blade
4) Wide open throttle RPM and speed with an average load (very helpful)
4800+ RPM and 49-50 mph.
5) Engine/drive make, model, year, and HP
Mercruiser 4.3l/4 bbl
6) Boat make model, year, length and weight
1994 Kayot Corso, 18', ~2500lb
So I'm thinking most likely a 4 blade, probably SS. Pitch is a question, considering I'm at or above the top of the rpm range already. Thoughts?
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