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  1. #1

    Default 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    Spent the spring breaking in the new motor. ran fine in a tank the whole time. 10-30 oil, 2/3rds up the stick to start. Took the motor and boat to the river two weeks ago and it started fine, oil light went from red to green. Put it in reverse and it started to miss and the oil light was red. Shut it down and pulled it out. Checked the oil and it was milky yellow. Drained oil and refilled to 2/3rds stick and in the water it did the same thing. Took it to a service center and they are checking it out. No evidence of leakage on the power head to water jacket???????????????? Now what.

  2. #2
    Join Date
    Sep 2010
    Location
    ontario
    Posts
    13,806

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    The dealer / factory will figure it out.------Or give you an other motor.

  3. #3

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    Thanks, hope so, only two weeks left in the vacation,darn.

  4. #4
    Join Date
    Mar 2010
    Location
    Buffalo, NY, USA
    Posts
    2,080

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    OK, something is goofy. The Tohatsu MFS9.8B does not have a green lamp of any kind. Not possible to go from red to green.
    If you need to flush an oil system due to water contamination, it will need to be flushed and refilled at least three times; draining the sump does not drain the oil pump or galleries.
    Paul
    Buffalo NY USA

  5. #5
    Join Date
    Mar 2010
    Location
    Buffalo, NY, USA
    Posts
    2,080

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    10 hours in a tank is not a break-in. You must load the motor. No way to get the proper loading in a tank.
    What does the dealer say?
    Paul
    Buffalo NY USA

  6. #6

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    The motor is a tiller handle MFS9.8B with the oil pressure sensor LED in the middle of the bottom cowl. Page 31 of the manual. The break in was with the unit in forward at the throttle settings needed, yes you get wet. 250 gallon tank. Hose on float to keep the level constant, not my first rodeo, but thanks. Dealer is confused about the milky oil, but repeated my condition at his shop. Started motor,, red LED, moments later it turns to green then back to red in about 20 seconds.

    Then he pulled the power head and inspected the gasket per the factory. Not enough evidence to indicate that it was the cause. They are considering the block might be "soft", or whether to pull it down more.

    I am waiting his next report tomorrow I hope.

  7. #7
    Join Date
    Mar 2010
    Location
    Buffalo, NY, USA
    Posts
    2,080

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    There still isn't any green LED... only red. Something is Very funky if you see green.
    However...
    If the motor was not run hot enough, the rings still have not fully seated. We usually figure 10 hours as the minimum; 20 with a lot of WOT is better. Even at that, there may be some slight oil gain due to ring blow-by. But that would not make the oil milky. Was the level high when milky?
    If the motor was never so low in the water as to get sea water in the intake or oil breather, there is either a head gasket leak or other [bizarre] defect. Cold oil pressure is about 40 PSI, whereas the water system is typically maybe 10 PSI, so it would have to be a massive leak, and I would expect oil discharge into the cooling water path as well. (Leak from high pressure to low, not the other way around). The only low-pressure, or suction in the oil system is at the oil pickup. The rest is under higher pressure than the cooling system.
    If it were in my shop, I would swap the power head under warranty (after conferring with the factory). Such a defect, while incredibly rare, could be either in the head or the block, so I wouldn't do just the short block.
    Paul
    Buffalo NY USA

  8. #8

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    Thanks Paul,

    Obviously, the time I put on the motor in the tank is not a "complete breakin" just what I could do before putting it on the boat and running it real time. Yes the milky level was high, at the top of the dip stick. I had only filled it to the recommended level. Tank time and river time was fresh water only. The dealer said basically the same thing and was waiting to hear from the factory as to what way to go. We will see. Darn.

  9. #9

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    Update on the LED color, you are right Paul, I thought it was green,but dealer says only RED. Must be getting old, ha. Still no update on problem resolution from dealer.

  10. #10

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    Update, under warranty, fixed. No gasket problem, gunk on oil pickup tube????? Would share a picture but not sure how to do it.

  11. #11

    Default Re: 2017 9.8 4 stroke with water in the oil after 10 hours of breakin

    The file got through for you to look at. Great. This is after he knocked some of it off.

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