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Carver 405 with 6BT prop size

Discussion in 'Carver Yacht' started by BIlljhs, Jul 17, 2024.

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  1. Capt Ralph

    Capt Ralph Senior Member

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    Location:
    Satsuma, FL
    Thank you brother.:)
  2. BIlljhs

    BIlljhs New Member

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    Jul 10, 2024
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    Toms River
    I understand and am thankful for the input....as you know there aren't any good options lately when it comes to buying a boat in this area....so with that I'm not afraid to buy it since I have been in contact with a reputable marine diesel mechanic who recently did all the maintenance and work on both motors to get the boat in shape for sale..the seller dumped almost 10k into this maintenance and besides a few punch list items it seems ok....I also lowered the asking price by over 20k so it put it in a reasonable price range for the vessel

    Now my only thing is I would like to find out what these things came from out of the factory in relation to the props...were they 20x22...22x22...20x 24???? Don't seem to be getting anywhere with that... I am hoping this winter when I take to props off that the prop service guy will know....

    Thanks guys!!!
    Bill
  3. ranger58sb

    ranger58sb Senior member

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    Chesapeake Bay, USA

    1998 boat. Just-previous owner had the boat for 18 years, and apparently didn't change or tune the props that came to him.

    Any reason to suspect any previous previous owners did anything to the props?

    My first guess is that they came as 20x24, and that many (most?) other instances of the same boat came that way too. Especially if you didn't see any additional size/pitch stampings that may have indicated alteration along the way.

    There's precedent for a builder actually changing props along the life of a model build, though... so in that case early iterations might have one size, later iterations a different size. Or sizing different props with different option engines.

    In our case, the builder did something like that, and apparently made the change very early on in the model production run. My guess, maybe coincident with the engine upgrade -- which started mid-way through the first year of model production -- though, and maybe builders wouldn't be fooling around much with prop specs barring other coincident major changes.

    -C
    Last edited: Jul 21, 2024
  4. BIlljhs

    BIlljhs New Member

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    Jul 10, 2024
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    Location:
    Toms River
    You are correct...the props are stamped with 20x24...the only indication that something is correct as far as the factory is the owner has a document that states the WOT is 2400 rpm....now also on the same sheet is a graph that shows 2600 for cruise and 2800 for WOT....the Cummins mechanic that worked on the boat doesn't think that Cummins would certify the boat from the factory with such low rpm....so at this point we are not sure if the first owner had something done to the props to lower the WOT to a lower value...the reason for that is unknown...
    I haven't moved the boat to my marina yet and when we get it here we will be diving into the issue and like I said in a previous post this winter I will be taking the props off and sending them to a local guy to be checked....

    I also wondered if the linkage that controls the fuel supply on the motors could have been monkeyed with to not allow WOT....I also wonder if that was the case the mechanic who surveyed the motors didn't find it????
    Interesting stuff and thank goodness I do all of my own mechanic work when I can....

    Thanks
    BIll
  5. Pascal

    Pascal Senior Member

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    Miami, FL
    Cruising only 200 rpm below WOT is way too high. Of these are rated at 2800 then cruise should be 2300/2400 not 2600

    a surveyor isn’t going to look at the throttle connections except to make sure the cables are tight. If they are not adjusted properly causing low WOT rpm, he will note the issue but he s not going to diagnose it.
    Capt Ralph likes this.