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Milky Grey fluid from Breath box (Over Flow Tubes)

Discussion in 'The Garage' started by TwinLewi, Jun 29, 2020.

  1. TwinLewi

    TwinLewi XS650 Addict

    Hello and good day gentz,
    1973 TX650 with a full motor rebuild top to bottom. New head, cylinders, 447 cam shaft, crank shaft, gear box etc.. the whole lot. It has 250 miles on the tac. Having a decent amount of oil and sometimes a grey milky fluid coming out of my overflow tubes that connect to the breather box and head of the motor. Motor was professionally rebuilt by the brilliant Geoff B. (Geoff's XS650 Parts NSW, Australia) and his wonderful Mechanic Mark. I got the lovely chance to be there and help out where I could.
    After the 250 miles of riding I drained the 2.5L of oil back out and checked the breather box for proper installment. Breather plates and gasket were there. It does have some of the steel scotch brite bits in the base of the breather box as well. I filled the bike back up with 2 Liters of oil and started over.
    Running the bike for 15 min, shutting it off for a 15 and starting it back up. Not riding it due to oil fly's everywhere and makes it look like there are other leaks. Some minor leaking may be coming from else where but that is another convo.
    I get regular oil leaking out of the breather tubes. After taking it for a 15-25km ride and stop I get a milky grey fluid coming out. Any thoughts, tips would be rad.
    Thanks for your time
     
  2. azman857

    azman857 '80 XS 650SG Rider XS650.com Supporter Top Contributor

    Milky grey oil usually means that there is water (condensation) mixed in the oil and needs to be run and brought up to running temps and long enough to let the water evaporate.
     
    gggGary, Paul Sutton, grizld1 and 2 others like this.
  3. TwinLewi

    TwinLewi XS650 Addict

    Hmmmm...
    Interesting. I have been told this before actually ya. When I first got the bike it had been sitting for a couple years outside. When I got her up and running it did the same thing. Someone gave me the same tip as you did. Figured there was a condensation build up and eventually it would clear. It sorta did but would come back time to time. Now I am thinking with a fresh motor rebuild how the hell would I have water (condensation) in my oil??? Wondering why it leaks oil as well. Crank pressure yes but new motor? Is this a break in thing and need to keep running it?
     
    Paul Sutton likes this.
  4. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    I would be asking Geof.............
     
  5. TwinLewi

    TwinLewi XS650 Addict

    yup already have! He was the one to tell me lower the amount of the oil and report back. Working with him. Just seeking more help/ info because I don't want to pester him. lol He is in NSW and I am in Vic.
     
    Paul Sutton likes this.
  6. bikefreakjon

    bikefreakjon XS650 Enthusiast

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    Milky white is water in the oil.
    Milky grey is aluminum dust or assembly lube.
     
    Last edited: Jun 29, 2020
    Paul Sutton, grizld1 and TwinLewi like this.
  7. bikefreakjon

    bikefreakjon XS650 Enthusiast

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    Do a compression test, the rings may not have seated or some other break in thing.
    That's the only reason I can think of for lots of oil out the breather.
    What is the ring gap? Piston to bore measurement?
    I think we all hesitate to point internet fingers at anyone but nobody is perfect.

    Good luck!
     
    Paul Sutton, grizld1 and TwinLewi like this.
  8. azman857

    azman857 '80 XS 650SG Rider XS650.com Supporter Top Contributor

    For rings to seal one needs to ride the bike. A lot. Some say Ride normal, no RPM limits. I'm of the Limit the RPM the first 500 miles and gradually raise the RPM as the miles add up and lots of oil changes. Do whatever your engine rebuilder says.
     
    gggGary, Paul Sutton, grizld1 and 2 others like this.
  9. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    Geof is a professional and makes money from restoring and building XS650's. Don't feel guilty about pestering him, he has to stand by his work.

    2000cc of oil is to little. The Electric start engines should have 2500cc of oil......

    Geof should have given a run down on how he likes his engines to be run in.....Taking advice on how to run the bike in, on here, could affect Geof's warranty
     
  10. TwinLewi

    TwinLewi XS650 Addict

    Will complete a compression test in the next day or two. Piston to bore is .25
    No one is perfect. We are all human. Just on here to ask for more guidance... experience ya da yada yada
    Cheers and thanks for the tips and questions
     
    gggGary, Paul Sutton and grizld1 like this.
  11. TwinLewi

    TwinLewi XS650 Addict

    Ya your spot on mate. Cruise and don’t rider her to hard. Don’t stay at one speed the whole time. Go up and down in the speed. Go to the hills.
     
  12. TwinLewi

    TwinLewi XS650 Addict

    Yup spot on. I am taking his knowledge and using it. Info and experience from other members online is only common ground and to better my personal knowledge. I am doing what he tells me and won’t disrupt that. Just like the chat on the forum. Learning all the time!!
     
  13. bikefreakjon

    bikefreakjon XS650 Enthusiast

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    Maybe you mean they are .25 oversize pistons?

    Piston to bore clearance should be .002-.0022 inches (.05-.055mm) unless using forged pistons or nitrous.

    The reason I ask is I have seen machine shops bore to just anywhere under the wear limit and call that good.
    A good machine shop should be able to give exact numbers.

    Curious how much oil are we talking about here? Pics please.

    Also, it is either no big deal or the engine will have to be taken apart again so don't be afraid to ride it.
     
  14. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    Something strange about all this..........

    What does Geof say is causing the murky oil ???.......

    If your communicating with Geof, why did you refill it to 2000cc of oil instead of 2500cc.........Did he tell you to???

    that is 20% less oil..........probably won't even show up on the dipstick......riding with a 20% reduction in oil will damage the motor..........
     
  15. stinky78

    stinky78 XS650 Enthusiast

    it seems weird to me too, pics really help, and it would be good to get an idea of how much oil we’ talking about, I’ve only rebuilt a couple of engines but they were all tight as a drum after, good compression before first start and then getting even better after being ridden, are you getting any smoke on start up? it’s normal to get some the first time you start it after a rebuild but it should be fine after that, also you said there was oil flying everywhere, can you elaborate on that a little? and you also said you ran it for 15min without riding it, normally when I run my bike without riding it, like when tuning it, I put a fan in front of it and turn it on once the bike is warmed up a little, air cooled motors need air flowing over them, let us know how your compression test goes.
     
    GLJ likes this.
  16. TwinLewi

    TwinLewi XS650 Addict

    .25 over I believe. It is a set of cylinders that have been bored out once. You can then bore out .5 over for the next build then .75 for a third. Sound correct? Sorry I didn’t do the machining and I believe that’s on the right track or my understanding of the rebuild process. I will seek exact numbers for ya and the compression as well. I will snap a few photo’s next time I start her up. I can send a photo of the cardboard underneath the bike from after a long ride I did. Thanks for your time by the way!!
     
    bikefreakjon, gggGary and Paul Sutton like this.
  17. TwinLewi

    TwinLewi XS650 Addict

    Geoff asked me why there was grey fluid coming out when I mentioned it to him. Ha he ask if I was adding water to the oil hahah
    He said it’s almost as if the oil is getting aerated. He said keep riding it and keep him in the loop. He was the one that told me to drain the oil and add in 2000ml or 2L. Said it wouldn’t hurt anything. ????? 20% leas sounds like a lot. It hits the dip stick just a nats under the first line.
     
    gggGary likes this.
  18. DaveO

    DaveO XS650 Addict

    Burning petrol produces a lot of water. Most goes out of the exhaust, Some ends up in the oil.

    C8H18 + 12.5 O2 → 8 CO2 + 9 H2O
     
    Paul Sutton and TwinLewi like this.
  19. 5twins

    5twins XS650 Guru Top Contributor

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    Yamaha issued a tech bulletin recommending this lower oil level for any owner experiencing excess oil misting out of the breathers .....

    [​IMG]

    So, you shouldn't do any damage running it lower. All the later bikes only run that much. But, none of this explains where the water's coming from, lol.
     
    Paul Sutton and TwinLewi like this.
  20. TwinLewi

    TwinLewi XS650 Addict

    And Fivetwins comes flying in to save the day! Hahah naw mate great info hear. Someone wlse shared something similar actually and it is good to know I won’t be causing damage. Wtf is this water b.s tho? Hahah
     

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