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Troubleshooting running gear vibration

Discussion in 'Props, Shafts & Seals' started by TahoeJohn, Jan 22, 2021.

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  1. DOCKMASTER

    DOCKMASTER Senior Member

    Joined:
    Feb 26, 2012
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    1,498
    Location:
    Ketchikan, Alaska
    Glad it was a simple fix. As to the why it got out of alignment, there are a number of things that can cause this: Motor mounts wearing or settling, cutlass bearing wear, boats can get a hog or sag in the them over time, etc, etc.
  2. NYCAP123

    NYCAP123 Senior Member

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    Glad you were able to get it corrected. Alignment can be a nightmare to get right. Sounds like your mechanic is a keeper.
  3. Retired Gunny

    Retired Gunny New Member

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    Mississippi
    So, i have a question along the same line. Just bought a 73 Bertram 46.6 and I have the delivery captain giving her a detailed look before she sails. The props had about an inch of growth on them. The boat had no vibration but after cleaning the props and at 920 rpm there is a bad vibration from the port side. Captain thinks it might be a loose annode on the shaft, he's going to dive and take a look. These are short low speed runs in a tight channel, nearest free water is about 30 miles south. The first run was at about 750 rpm the second at about 950. thoughts?
  4. NYCAP123

    NYCAP123 Senior Member

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    If the props had an inch of growth what must the rest of the bottom have? Haul, clean the bottom and you can check the anodes at the same time.
  5. Retired Gunny

    Retired Gunny New Member

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    Mississippi
    Yeah, the captain has already scraped the bottom. Just have to wait and see what he finds on the next dive.
  6. motoryachtlover

    motoryachtlover Senior Member

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    smithfield, VA
    A rope, a piece of plastic, and anode are all possibilities especially since it is happening at low RPM. I agree with NYCAP that I think a haul out is in order. When growth gets extensive I question the ability of a diver to get it all. I cleaned my wheels once (just the wheels) and it was a work out. BTW used to have a Bertram 42 MY. It was ugly but a bruiser.
  7. Retired Gunny

    Retired Gunny New Member

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    Jun 24, 2022
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    27
    Location:
    Mississippi
    Found a bad cuttlass bearing. Anyone know the bearing size for a 2" shaft on a 73 Bertram 46.6 sportfisher?
    Bystander likes this.
  8. ameriboat

    ameriboat New Member

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    Feb 22, 2011
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    Location:
    lake michigan
    Here is my 2 cents on the vibration I looked at the exhaust support arms and 1 of the arms was screwed out to the ceiling
    and after I ajusted it the vibrations stopped