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Oil change for Yanmar 6LY

Discussion in 'Engines' started by Bahma, Nov 12, 2016.

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  1. Bahma

    Bahma Member

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    Apr 10, 2013
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    Man o War Cay Abaco Bahamas
    I'm changing the oil and filters in my Yanmars, and an wondering because both filters are empty of oil, is it safe to start the engines, I fear the bearings may be starved during the time it takes them to fill.

    My engines are so rigged that I cannot roll them over sithout them starting immediately.

    I'd really would appreciate any thoughts by the gurus on the excellent site.

    Many thanks.

    Norm
  2. bobhorn

    bobhorn Member

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    Can you not fill the filters with oil before mounting them?
  3. Capt Ralph

    Capt Ralph Senior Member

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    I was reading a Cat manual and found similar comments in a Cummins manual
    "Mount fresh filters dry and empty".
    The Cat manual explained "to ensure no debris is entered into the system".
    Both manuals stated the empty filters would be charged quickly by the engine and re-check oil level after a minute of running.
    I run ole 12v71TIs with two monster oil filters mounted sideways, no way to pre-charge them. There full 2 seconds after starting

    There is a Yanmar HO model that has two monster oil filters mounted on top & sideways.
    Amazing how fast they fill.

    We all want to pamper our engines and help when we can.
    This is a good thought, just not necessary.
    I service boats, I stopped pre-charging filters long ago.
    I'm pretty sure your mfg manual will state install empty and dry also.
  4. Bahma

    Bahma Member

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    I thank you for your prompt replies, indeed the filters are mounted horizontally and would be impossible to be filled with oil, without pouring it all over the engine.

    Never thought about mounting empty filters with my Jimmy 671s, but these expensive Yanmars give me the fits.

    I shall go forwards with confidence.

    Thanks again.
  5. bobhorn

    bobhorn Member

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    Learn something new every day. I have a Mazda RX7 where the filter is mounted upside down. Impossible to fill but the original engine lasted more than 200,000 miles so mounting it empty didn't seem to hurt the engine. Before removing that filter I always punch a hole in the top, this helps to drain most of the oil before unscrewing it.
  6. Bahma

    Bahma Member

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    Location:
    Man o War Cay Abaco Bahamas
    I guess I didn't think it through, but when I removed the old filter no oil ran out, so I believe they must drain at least half the oil out after the engine was last shut down. Yanmar designed a small well in the casting which drains into a plastic tube...thence to the bilge.
    There was no oil dribbling this time.

    So there must be air in the filters each time the engines are started.

    Interesting about the Mazda, I've never seen an upside down setup.
  7. Capt Ralph

    Capt Ralph Senior Member

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    I have learned a few more things.
    Don't punch an oil filter in the bottom center. The punch, paint, metal from the new hole and dirt just went into the clean (discharge) side of the filter and will drain into your engine.
    Punch towards the side.
    On the side oil filters like that Yanmar and my DD, warm up and pump the oil out the night before.
    The next morning, double up on some heavy duty garbage bags, wrap your super bag around the just loose filter, unscrew the (Not Hot) filter and let the filter and (Not Hot) oil drop into the super bag.
    Fresh double bag for every filter.
    Then re-pump out the sump to remove what drained down over night.

    For the guys that really want to pamper your oil change. Pour or Pump a few qts of oil into the engine. Then pump it out.
    I kind of think this helps rinse the sump one last bit but more importantly, it cleans the oil lines and pump.