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1 piston down? white smoke, rough riding...

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by mattb, Feb 22, 2007.

  1. I'm heading down the Great Ocean Road this weekend for a much anticipated ride, but my bike's behaviour as of this week is worrying me.

    Twice now in the last fortnight, my bike, which never otherwise blows any smoke, blew great and very white clouds. After a warm up and some revvs, the smoke completely dissipated. The second time - last Monday - that it did this, the bike had shown no hint of this all day (I had been riding, and indeed I ride the thing daily). This second time, I was riding along about two kms later, and suddenly the engine went rough and lost a lot of power - the exact same phenomenon as when it was once running at least one piston down due to a pulled hose. I pulled over immediately, and it immediately came right, and gave me no more problems. This morning I rode into Uni - no smoke - and as I was slow-riding the bike into a parking position, the same phenomenon happened again, albeit very subtly and only for an instant, after which it was fine and didn't return, and hasn't again today.

    Any ideas of what might be happening?

    If it helps, two other recent events:
    1) The bike has been getting an oily/greasy build up on the battery terminals, causing it sometimes to short out.
    2) The head gasket blew even more - over a month ago I was freeway ridng two-up in stinking hot weather and suddenly there was a subtle loss of power, whcih quickly came right, though since then it bleeds a lot more oil.

    The bike is a Kwaka GT550, 135,000kms, belly full of engine noises, and hasn't had a service since before it was made! If anybody can give some suggestions, I'll try inspecting them before i head off down the GOR. A friend wants to go pillion, so I also need to think about whether that will add risky pressure to the engine.

    Thanks, Matt.
  2. If it hasnt been serviced since it was made or so long ago that u cant remember maybe that would be a good place to start :grin:
  3. Is it water-cooled? I'd be a little concerned about that head gasket too.
  4. Not water cooled, (as far as I know), so it's not coolant. The usual other source of white smoke is certain kinds of brake fluid, but that would only get into the exhaust through a vacuum booster, and I'm pretty sure you wouldn't have one of those on a GT (?).
    Did the white "smoke" hang in the air like actual smoke, or did it evaporate (in which case it is steam (water)? Are you sure it is not really blue oil smoke? Can be hard to tell in bright sunlight.
    If it's steam, my first thought would be that you've got water in the tank, which would also cause it to run rough until you burned it off.
    If it's oil smoke, the fact that it stops smoking after a while, suggests that your burning oil that has seeped into the bores while the bike is at rest. Which points to valve guides or possibly head gasket.
    The sudden loss of power (loss of a cylinder or two?) suggests either ignition/spark problem or sticking valve, but that would be accompanied by black smoke, not white.
    Describe the noises.
  5. Matt,

    This era Kawasaki air cooled engine can force oil through teh breather tube into the carbs under certain conditions. If the oil is overfilled crankcase pressure can force some oil up and so can an older engine with a fair bit of blowby.
    I've had it happen on my old Z (same engine family).
    You can possibly take your crankcase vent cover off teh gearbox and give it a clean out, plus the hose, or you can run a longer hose out of the crankcase bearther and out the side of the bike, directed AWAY from teh rear tyre. I'd probably do this on your bike.
    I can't see oil getting into teh combustion process on these bikes any other way.
    As for the head gasket and loss of power, it may well be your valves need adjusting. When these engines get hot (like traffic or hot days/hard flog) the exhaust valves grow in lenght due to heating up and close teh clearances up to nothing on the cam. This is not too noticeable initially, but at slow speeds, the engine will get REALLY cranky, and may stall when coming to a stop after a hard run or in heavy traffic. A head gasket on these engines wil manifest as huge amounts of oil blowing out of teh gasket, very obvious.
    SO, I'd change the breather, and do a valve adjustment, which is a slightly involved process, as the engine probably has shim under bucket adjustment, which means pulling the cams to do the adjustments.

    Regards, Andrew.