Prop Selection - Starcraft 196 Fishmaster

carpedium

Petty Officer 1st Class
Joined
Jun 20, 2011
Messages
258
Current rig has a 115hp 4 stroke. At WOT the tach shows around 5200 RPM when properly trimmed, with 25 gallons of fuel gear and two people. The manual says that the motor should operate between 5500 and 6000 RPM at WOT.

There is currently a 3 blade 17" prop on the motor. It ventilates easily on turns right now, but other than the low RPMs it performs ok. From my research it looks like a 4 blade prop may be the way to go. I am looking at a 15" four blade, since the iBoats selection guide says that will get me to around 5800 RPM WOT. Any recommendations or experience for a fishmaster 196?

The prop I'm considering:

http://boatpropellers.iboats.com/Mer...t_id=937444230

Any help is greatly appreciated.



1) Performance issue you are trying to correct.

Motor seems to "bog down" and not reach recommended WOT RPM.

2) Current prop manufacturer, model, aluminum or stainless as a minimum.

The existing prop is a mercury black max 17" Aluminum - 4877344A4517P

3) Current prop diameter and pitch (required).

13" Diameter and 17" Pitch

4) Wide open throttle RPM and speed with an average load (very helpful)

5200 RPM @ 33MPH with 700lbs people and gear, plus 25 gallons fuel.

5) Engine/drive make, model, year, and HP

Mercury Saltwater 4-stroke EFI 115, 2004

6) Boat make model, year, length and weight

Starcraft Fishmaster 196, 2004, 19.5', 1430lbs dry.

Edit: - Boat has a outboard mounted hydrofoil.
 
Last edited:

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Would be nice to see your lightly loaded wot rpm and gps speed without the foil.
Why is the foil there? The foil could easily eat up a couple of hundred rpm.
 

carpedium

Petty Officer 1st Class
Joined
Jun 20, 2011
Messages
258
The foil was there when it was purchased. I guess it had trouble getting on plane before. The boat has a 19.5 degree deadrise that continues back to the transom, so I'm sure that factors in as well.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
With the need to improve the rpm and possibly the hole shot a 4 blade may be in order.
It may also help with the ventilation.
Something like smart tabs would be better than the foil.
 
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