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PROBLEM. help? perkins 4.108-not taking load well

Discussion in 'Engines' started by Calvin19, Feb 2, 2008.

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  1. Calvin19

    Calvin19 New Member

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    Location:
    San Diego Bay
    Perkins 4.108, in a 40' Yorktown cutter rigged sloop.

    she starts now, idles fine, and in NEUTRAL she will rev to full RPM without issue.

    IN GEAR, at around 2000-2500 RPM, she loses power, vibrates violently, and spews gray smoke out the exhaust.

    fuel MIGHT be old, we added 10gal diesel to her today, we think there was only about 5gal in her to start. has not been run in 6 months.
    oil is good, no water in separator, but a bit milky.

    any ideas?
    we are trying to get out, need to leave our Marina ASAP.
  2. Marmot

    Marmot Senior Member

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    "... but a bit milky."

    I think it is trying to tell you something.

    Start with dumping all the old fuel, flush the tank, change the primary and secondary filters and try it again.
  3. Norseman

    Norseman Senior Member

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    Good advice:

    I have a Perkins 4-108 in my boat and found it to be bullet proof, but not idiot proof..:D

    All it is asking for is clean oil and clean fuel, given that it will run happily forever.:cool:
  4. Calvin19

    Calvin19 New Member

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    Cool.
    Already bought the filters, and tanks for diesel disposal.

    now, how do I flush a 200gallon fuel tank?

    there is 15~ gallons in it now.
  5. Calvin19

    Calvin19 New Member

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    I also assume I bleed everything... I'm putting in a new Seperator as well. Just in case.

    Basically, clean everything fuel related in the whole motor? I can do that. still need to figure out how to flush a 200gal diesel tank.
  6. K1W1

    K1W1 Senior Member

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    Hi,

    If you have an inspection hatch open it up and have a look in your tank.

    You can suck out the fuel in there with one of those hand siphon pumps and then wipe the tank as clean as you can with rags, or if you can't get to the deep part of the tank that way connect an electric pump on the end of a drill or similar to your fuel line that feeds the filter and pump it out that way. When you have sucked out all you can add a couple of gallons of fresh fuel to the tank and then pump out and dispose of that as well.

    As your motor actually starts and runs you will probably be lucky enough to get away with replacing each filter and cleaning the bowl that they go in, you should also slacken off and drain the fuel lines between the filters, there is a small bonnet on the fuel lift pump that can also be taken off and cleaned out.

    The 4.108 is a great engine and will withstand lots of hard work but like anything mechanical a little TLC goes a long way to reliability which is one of the most important things you need in a marine engine.

    If th boat is going to sit for a while I would add some Fuel Biocide to the tank as well Biobor is a frequently found one in the US. Racor also make their own one as do many others. Fuel Growth can build a resistance to a certain biocide like humans build an antibiotic resistance changing between brands of biocide occasionally is also a good idea.
  7. Norseman

    Norseman Senior Member

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    It has been done before.

    Ya are lucky to have a 200 gallon tank. Hopefully it is Aluminum as opposed to to black iron?

    Suck up the remaining fuel and discard it.
    Clean the inside walls/bulkheads/dividers/etc with paper towels and Windex if ya can get yer arms and hands in there. If not, use high pressure fluids.
    (Some of the commercial tank cleaning places will use yer own diesel to clean the tank with a HP pump/Filter/Suction tube, etc.)


    Ya mean a bowl for the -500 series Racor with the water separator in the bottom?
    Not sure the fuel flow is enough on a 4-108 to really separate the water from the fuel: Less than 1 gallon per hour is kind of slow motion..

    I would rather recommend a Racor Vacuum gauge: It will tell ya all about contaminated fuel and/or dirty filters.

    Any TLC however will keep that 4-108 running forever:
    A guy I know in St. Croix put 15,000 hours on his 4-108 before he overhauled it. Nothing wrong with the engine, but the hours made him nervous as he was running a charter boat.

    :cool:
  8. Calvin19

    Calvin19 New Member

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    no time to get a pressure fluid clean, I drained it, and let some 911 sit in it for a while, then drained it again, dropped a remote camera in there, there is still rust-colored growth, but it will not budge, even from a metal stick poking at it. I'm leaving it.

    replaced all fuel lines, seperator, and filters.

    should have her up again in the morning. departure plan for tuesday sunrise.

    thanks for everything guys! ill let you know how it goes!
  9. Capt. Joe

    Capt. Joe Guest

    Too bad nobody had any input re the oil being "a bit milky" :confused: - that's what would be worrying me more than anything else, especially since he mentions "grey smoke", which could be that she is burning water.....
  10. AMG

    AMG YF Moderator

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    I think he was describing the fuel, not the lubrication oil. Let´s hope the trip is going well anyway...
  11. Marmot

    Marmot Senior Member

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    The OP wrote: "... oil is good, no water in separator, but a bit milky."

    I read that as the lube oil is good. The fuel in the separator is a bit milky.

    It is extremely doubtful if someone with a Perkins 4-108 in a 40 footer has installed a lube oil centrifuge.
  12. K1W1

    K1W1 Senior Member

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    Hi,

    I agree with the two comments above and feel the milky reference was concerning fuel.

    Even if it were running a centrifuge there would be water in it as water is needed to get the seal in the first place.

    Calvin, Can you please take the time to let us know how you got on and if your milky reference was about the fuel?
  13. Capt. Joe

    Capt. Joe Guest

    OK, sorry fellows I guess I didn't have my reading glasses on..... :rolleyes: