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  1. #1

    Default Yanmar Kanzaki KM4A

    Kanzaki KM4A mated to 4JH4AE. Forward gear works fine, but frequently will not select reverse, or reverse comes in only at high revs.

    Any ideas please.

  2. #2
    Join Date
    Sep 2010
    Location
    Jersey Shore
    Posts
    5,215

    Default Re: Yanmar Kanzaki KM4A

    Your Gear has a cone clutch, Delayed engagement is usually caused by the cone clutch getting glazed. It is important to run the correct gear oil in a cone clutch transmission.
    Yanmar recommends:
    3JH4E, 4JH4AE: • SAE Viscosity #90 or 80W90 • QuickSilverŽ 1 High Performance Gear Lube.

    Years ago when a delayed shift would happen in transmission with a glazed cone clutch, we would replace the Gear oil with Diesel Fuel, run the engine and shift it in and out of the gear that was delayed a bunch of times, drain the diesel and fill it with the recommended oil . It worked.

    These days I will tell you to pull the gear apart and replace the clutch. What you chose to do is up to you....Make sure you use the correct oil when refilling..
    Chris
    Dockside Marine Services
    Jersey Shore.
    Mercruiser/Mercury Certified
    Let the insanity begin.

  3. #3

    Default Re: Yanmar Kanzaki KM4A

    Chris.

    Many thanks for that info. Will give it some thought.

    Geoff

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