proper prop?

[Tim/Rinker192]

Just bought a 2007 Rinker 192SE with Mercruiser 5.0MPI 260HP. It came with 14.5X19 aluminum 3 blade prop. Rinker tech rep tells me it is the correct prop for the boat. I believe I should be getting better performance across the spectrum. The hole shot is OK but but the boat labors to get on plane with a few passengers and a skiier. It's diffucult to keep it on plane below 20mph. The tachometer says RPMs are 5600 and the GPS speed is 50mph at WOT when just me and the wife are on board. It turns a few less RPMs with 3 kids along. Specs say WOT should be between 4600 and 5000 RPMs. I never hit the motor's rev imiter so I assume the tach is incorrect. I want to try a different prop but don't want to hurt the holeshot nor hit the rev limiter. Gas consumption is good so far (~5gph) but I have not run it hard for too long yet.

I've been told to do almost everything from adjust the pitch, to add trim tabs, to add a whale tale to the drive, or to add cupping to the current prop. Dealer wants to sell me new prop. He's not much help. Any input will be appreciated.

 

[gcboat]

Re: proper prop?

There is always a fine balance between the boat's recommended performance and what the owner needs / wants. If all things considered such as a recently tuned engine, fresh fuel and NO passenger's on board then those specs are met. But as you mentioned add some bodies and all goes down hill.
Well, that's just the nature of the beast. There can't be a "perfect" prop for all of your situations.
As far as adding a whale tale - NO - not worth it. Trim tabs ( Smart Tabs ) might be worth looking in to. The prop should be cupped from the factory. Maybe not to the degree of a racing edge but it still should have a factory cup on it.
If your dealer is a nice guy he should offer you the option of exchanging props until you find one that meets your criteria. Of course if you break it you bought it.
A thought would be to look at a four bladed unit. You will have a good hole shot but loose some on the top end - which is important to you?
Now an aluminum prop vs. a SS prop will act a bit different. They'll run stronger and harder but will present problems when you ( if you ) should strike something.
Nothing is ever perfect on a boat - you need to decide what is more important to you. Too many variables.

 

[Bondo]

Re: proper prop?

Ayuh,...

This is a Double post,...

The original thread is Here....