Oil change time-what oil would you use?

Discussion in 'Boat Repair Help' started by Mark R., Mar 3, 2007.

  1. Mark R.

    Mark R. New Member

    Messages:
    186
    State:
    Rush Springs, OK
    I have 1979 OMC 140 hp motor, what weight oil would you use?
    5w-30 or a 10w-30 or 40?
    Maybe a High Mileage or Truck and SUV oil?
    It only has 648 hours on the hour meter.
    Thanks,
    Mark
     
  2. squirtspop

    squirtspop New Member

    Messages:
    968
    State:
    Glencoe, Arkansas
    For the boat I use Quicksilver. In the truck I use Valvoline 10-30. In the riding mower I use Havoline 30
     

  3. fishhook

    fishhook New Member

    Messages:
    658
    State:
    Willow Woo
    I use Havalene 10W-30 in all of my gas 4 stroke engines including, boats, lawn mowers and wife's Expedition.
     
  4. Grumper

    Grumper New Member

    Messages:
    2,277
    State:
    Crystal City MO
    I used to manage a oil change place for about 5 years. Believe it or not people did bring their boats in for us to service. I usually ended up putting Valvoline 10w40 in them. I'd probably use that.
     
  5. Mickey

    Mickey New Member Supporting Member

    Messages:
    14,592
    State:
    Illinois
    On all my trucks, cars and lawn mowers I use Castrol Synthetic 10-30. A great oil but expensive.
     
  6. jim

    jim New Member

    Messages:
    2,579
    State:
    Jacksonville NC
    I cant tell if your engine is a sterndrive or an outboard but I will make this recommendation.Time and again I have read in all the boating mags that Marine oils are formulated different because of the high moisture problem.Lets face it marine engines are in the water.The marine grade oils are specially formulated to offset the moisture problem,which causes sludge and acid build up.Contact OMC or a dealer and find out what the recommened oil is and use it.Simple as that.:smile2:
     
  7. slickrick

    slickrick New Member

    Messages:
    20
    State:
    oklahoma
    I agree with Jim, I have a 79 Johnson Stinger 75 hp. I don't use anything but Johnson. So whatever manufacturer you may have always use there product, you will have less problems.:cool2:
     
  8. Mark R.

    Mark R. New Member

    Messages:
    186
    State:
    Rush Springs, OK
    Jim after opening up my starter today I have to agree a person needs to use a marine oil.
    My starter was a mess inside due to the condensation in the motor compartment, I would have never believed it could be so crudded up and still run.
    Same thing has to be going on in the motor sucking in the wet air.
    Thanks,
    Mark
     
  9. clintonhawg1

    clintonhawg1 New Member

    Messages:
    177
    State:
    indiana
    I like napa brand oil it is made by valvoline and is 50. cents cheaper .But for the boat i would stick with the what omc recommends .I use nothing but quicksilver products for my merc.