Bayliner 4788: Spare Prop Mystery

[Technomadia]

We are in a boatyard in Miami having our recent submerged channel marker damage repaired.

The guy from Lauderdale Propeller came to asses our damaged props, and he also took a look at the spares we had found on board. He pointed out to us that they were two totally different styles of prop, and that he wasn't even sure the spares would fit properly - "you may just be carrying around expensive paper weights"...

The props that were already installed he recognized as a common bronze Michigan DQX prop - he took them off to be repaired and scanned. He left us with the mystery props to figure out.

Does anyone recognize these?

Should we put the spares or the Michigan (after repairs) props back on our Bayliner 4788?

Thanks!

- Chris

[ksanders]

The ones you took off look as you indicated like a standard Michigan Wheel prop.

The other props look like the OEM props.

AS a OEM Bayliner used a special prop made by Nakashima to get the performance they wanted to reach the market demographic for the 4788.
The props were originally 24d X 24P, which is a bit overpropped for most peoples loaded weight on the boat.
I run a set of Nakashima 24D X 21P props which is about right, or maybe on the underpropped side, which is far better for the Cummins engines.

In the end, if you run your boat at displacement speeds all or most of the time you probably won’t see much of a difference between the OEM and the Michigan Wheel props you had on the boat.

[Woodsea]

I am no expert but from what I have learned, I wholly agree with Kevin. 24x24 props were shipped as standard and they are over propped by a bunch in the real world of how our boats get loaded and used. It does not look like yours have been repitched. When the prop shop scans them they should be able to tell what you have. I would use this opportunity to repitch. I also had a spare set of props aboard and they were 24x24 as well. I have the 370’s and I repitched my 24x24 down to 24x21. Not only did my rpm come up a lot closer to the safe zone of 3000 rpm, the boat just ran way better! My goal is to get 3-5% over that 3000 rpm fully loaded on a hot day per Tony Athens recommendations. If you have 330’s then 3-5% over 2800 is what he recommends. I’m in the process of either repitching again, down to 24x20.5 this time or buying new and selling my 24x24 spares. I think you will be really happy making a pitch change. I certainly am even with my “educated guess” first attempt. Good luck!

[Cptmorgan]

Yep, those look like the OEM props. They are good props, but yes, they should be pitched down for running at high speed.