oil coming out exhaust pipe

Discussion in 'The Garage' started by kman40, Dec 20, 2009.

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  1. kman40

    kman40 XS650 New Member

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    Sarnia
    okay ,just bought bike. it starts runs on one cylinder then the other cylinder kicks in only to backfire and puke out large amount of oil.Is there oil passages that could be plugged in the top end?
     
  2. Travis

    Travis Staff Member Staff Member

    Time for a rebuild!
     
  3. Travis

    Travis Staff Member Staff Member

    Thought I would elaborate on this a little moreā€¦ If you're sure it's oil coming out of the exhaust and not just condensation and carbon, you either have a hole in that piston, bad rings, or bad exhaust valve seal/guide. All require pulling the motor and taking it apart.

    Have you checked the compression on that cylinder? Not that it's going to matter since you're going to have pull the motor anyway, but just curious. If you don't have the money, time, or knowledge to fix that motor, you could probably get a good used one for about $100 US that should get you going again in no time. It would probably be cheaper and easier anyway. Let us know what you figure out.
     
  4. xs650rider

    xs650rider XS650 New Member

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    mate i had the same problem my xs had a hole in the piston check out my photos best thing to do is pull it appart iv got a spare piston if thats what it is
     
  5. kman40

    kman40 XS650 New Member

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    Okay I pulled the engine out of the frame.Took the top end apart and found that 1 piston and rings first over .25.The other piston the one that throws oil everywhere is standard piston with .25 over rings.Would this cause that much oil to come out the exhaust?Thanks for all the information..
     
  6. inxs

    inxs xx

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    - check your piston to cylinder clearance...if its 0.10mm or more its too much
    - decoke the piston including the ring grooves and make sure the oil relief holes arent blocked
    - check the piston for damage...pitting, cracking, scoring or broken sections in the crown, ring lands and skirt
    - if you have your cylinder off, after cleaning the piston and rings put the rings back on the piston, invert it and slide back into the bore...stand over a white surface or light box...you will see if there is a gap anywhere

    - the oil expander rings also have a tendency to compress...you can retension them if youve got 3 hands...this wont work if you have too much piston to bore clearance
    -need a 75mm pipe or old piston...oil the outside surface​
    -slide the expander ring over the outside surface​
    -hold one end to the surface​
    -hold the middle against the surface-no gaps​
    -pull the other end towards the fixed end..ie. stretch it slightly...you only need a few tenths of a mm...when you refit the piston into the cylinder they will come to a natural balance​
     
  7. supercooper04

    supercooper04 XS650 Enthusiast

    On mine. The bike had stood for ages. After running it up. The exhaust is really oily and you do get a good drip from the exhaust. The engine doesn't seem like its loosing a cylinder. But when its hot it has a valve tap. Adjusted the valves as per spec. but it is worrying.
     

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