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Centaflex PTO coupling

Discussion in 'Stabs, Tabs & Gyros' started by TahoeJohn, Dec 28, 2020.

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  1. DOCKMASTER

    DOCKMASTER Senior Member

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    Feb 26, 2012
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    1,396
    Location:
    Ketchikan, Alaska
    It shouldn't be too difficult or expensive to get a machine shop to make you a new spacer if you can't find one. It's doubtful that was installed just for the fun of it so I wouldn't omit it. It's either acting as a thrust washer or making sure to separate the rubber from the face of the engine output flange or both.
  2. TahoeJohn

    TahoeJohn Member

    Joined:
    Aug 8, 2020
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    Tahoe VIsta
    Yes, I'm of the same mind. Yesterday I ordered a chuck of bronze and will get this milled up. Shouldn't be a big deal.

    I haven't heard back from Horizon yet but they did say that they are researching it. More than anything, I'd just like to hear what their reason is for this spacer.
  3. TahoeJohn

    TahoeJohn Member

    Joined:
    Aug 8, 2020
    Messages:
    155
    Location:
    Tahoe VIsta
    Yesterday we got everything reinstalled, with a new Centaflex coupling and a rebuilt Spicer driveline. All the vibration from that PTO is now gone, verified by bringing the engine up to speed with the gears in neutral.

    We then took the boat out and there is still quite a bit of vibration on the port side around 1400 RPM. It's better above and below that speed. Question 1: Any recommendations for a good marine engineer in the San Francisco Bay Area? I'll need to start looking at the running gear next.

    Second question: The control panel (picture below) for the ABT Trac thrusters beeps a warning and flashes the "check system" light when the system is enabled and RPMs exceed 1100. Is this to be expected? From reading the manual, I understand that the clutch is supposed to disengage above 1100 and re-engage below 900 RPMs, but it's not clear whether this is expected to happen by itself (silently) or whether it will always beep the error code, meaning that I always need to remember to turn the system off once I'm done using the thrusters around the dock and am out cruising. Not a huge deal; just curious to hear if this is normal. Thanks!

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  4. BRyachts

    BRyachts Member

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    Mar 31, 2006
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    Location:
    Ft Lauderdale
    I had a similar situation with the dis-engagement of thruster at increased RPM's on Cat 3512's. What we did was have a small bracket made up that mounted on the underside of the throttle cable at the governor, and attached a rugged microswitch directly contacting the throttle cable. It was adjusted so that as you raised RPM's, when you got to 1000, the microswitch would open, dis-engaging the thruster pump.
    There was still the on/off rocker switch on the dash for master control, but with the micro in place, in case the Capt had to raise the throttle for maneuvering it acted as a safety and tripped out the system and would only re-engage once the throttle was lowered back down to slower speed. (below 1000)
  5. DOCKMASTER

    DOCKMASTER Senior Member

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    1,396
    Location:
    Ketchikan, Alaska
    I suggest you start a new thread to get input on troubleshooting your vibration. Lots of good input from folks here to be had. You will want to start with the easy stuff first like prop inspection and alignment checks.