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Yanmar 6ly2a-stp 440 problems

Discussion in 'Engines' started by 1ayacht, Oct 6, 2010.

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  1. domenicis

    domenicis New Member

    Joined:
    Dec 20, 2017
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    Location:
    Lynn Ma
  2. domenicis

    domenicis New Member

    Joined:
    Dec 20, 2017
    Messages:
    14
    Location:
    Lynn Ma
    I have a luhrs 36 with the 440s and they have 1400 hours on them the only problem i have had is the number 5 fuel line snapped on both engines two years apart
  3. Boatbuilder

    Boatbuilder New Member

    Joined:
    Jun 27, 2011
    Messages:
    29
    Location:
    Anacortes WA
    Post 34 has probably your best info, at San Juan we switched from the 370 hp to the 440’s when they became available.
    The best defense you have is to simply verify Serial numbers and ask if the valves have been replaced, the most common method was to just replace the whole head.
    Yanmar had a bad run of valves early on for the 440’s, and have refused to man up.
  4. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    9,665
    Location:
    Satsuma, FL
    Fuel lines snapping is just a fatigue issue that happens. The science behind a small steel line cycling such pressures swings up to 1700 times a minute are tremendous. Then the harmonic developed from the engine and this lil steel tube flying around with in it unsupported 2, 3 to 5 inches in length. Keeping or adding more fuel tube inter connect tube clamps may help.
    Sadly, Ship happens.

    It is a gamble that you have the good valves/heads. Probably the better side of the poker hand.
    I understood it was near 90% valves and some 10% valve seats that came apart. Please read my above post before I start a repeating post here.
    I doubt Yanmar USA has a good track of their replacements, Self replacement, court ordered replacements or how many heads/engines are dropped in the ocean. I do admit, Yanmar did not care and their gamble worked. They still sell a **** pile of engines,, un phased.