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New Pistons and Rings?

Discussion in 'Technical and Troubleshooting Torque' started by dr650, Sep 29, 2005.

  1. Hi guys i just had the following work done ** remove head
    recondition head
    reshim head
    new coolant/head gasket and stem seals...cost 560 aussie dollars

    now there is alot of white smoke on start up.I took it back to the shop straight away.They now claim that i need new piston and rings.They have to pull the motor apart AGAIN.

    Is this a must the smoke goes away after about a minute.Are they just trying to get more money out of me or is it necessary.The bike has 8500 km's..klx 650

  2. was it blowing white smoke before they pulled it apart?
  3. Id take it for a ride. You'll find the smoke may clear up. Its usually caused by lub and gasket stuff that gets on the piston and head during assembly. Do a decent ride on it (50+ks). If its still there then you may need new pistons and rings. Does your bike have a radiator or is it air cooled?
  4. It is water cooled.Smoke is only on start up goes away after a minute or so...cheers
  5. Does it smell of burning oil?? is the smoke blue/white?? How does the oil look after a ride?? How much is missing??

    If the answer is nope to the above... than it could be just crap in the cilinder or on valves... just ride the thing and observe it... see if there are any fluids missing... oil, coolant...
  6. Sounds suss. What did you have the engine originally serviced for (what problem, that is)?

    Usually, when an engine blows smoke on starting and then clears, usually indicates that it's leaking oil past the seals around the valves. As the engine sits there, the oil around valves drains down into the cylinders. When it starts, the oil gets burnt out. What's in the exhaust that gets blown out during this process continues to burn out as it warms.

    If you had the head off for valve work, I'd suggest that they've stuffed something up. Usually, workshops, well, reputable ones, offer some kind of repair warranty. I'd be insisting on them looking at that first, before you commit to any possibly needless repairs.

    If they give you hassles, give your state's consumer affairs mob a call and explain the situation. They'll be able to advise the best course of action.

    Good luck
  7. OK the reason why i had head gasket replaced etc was that somehow a piece of plastic somehow was holding the valve open causing the bike to loose compression.They had to take the head apart to find this out.The head gasket has just been replaced hence my concern with white smoke...They tell me it is not a hg problem but rings..but again they wont no till they pull the motor again.I told them that i thought white smoke was water or coolant..they say no.But again they say they have to pull the motor again to find out.There was no prob with smoke before the work was done...

    Have checked for oil and coolant lose ..nothing so far.
  8. No smoke before the head reconditioning.
    Smoke after head reconditioning.

    Any workshop trying to convince me that anything other than a shoddy job on their part was causing the problem would see me coming back with a spiked bat and asking, politely, for a refund.

    I'd drop the oil and check if there's any milky residue in it, indicating coolant contamination. I'd bet you a glazed doughnut the muppets bollocksed-up the head gasket installation.
  9. That is the first thing i did when i got the bike back.No problem with oil nothing showing in the new batch through the site glass either.The bike runs fine except for the smoke at start up.I really dont want them to open the bike up again...Should i just leave it for now and see how it goes??Or is it a must to get this problem resolved so as not to damage the bike?Cheers
  10. I kinda lean to cowboy's interpretation, though everyone else (and me) is justified in being suspicious. I'd give it a good run then let it get dead cold and start it again. If it does it again then borrow IK's spiked bat and revisit the matter.....
  11. Yeh. We, kinda, need more information.

    How many times have you run the bike since the head reco?

    How far would you have ridden it, in total?

    Does it blow smoke from cold only, or even if it's started after only a short pause?

    Map out the problem a bit.

    An enduro bike like the KLX650 has wafer-thin outer walls. You'll be able to hear pretty much every rustle and tinkle of the parts flailing about inside while the engine's running. If it doesn't sound like World War III (baseline enduro bike engine noise levels being taken as equal to the Normandy Landings) in there, chances are you're not doing any damage by letting it run, so you might as well ride it around a bit, find out exactly when it makes the smoke signals on startup.

    How plausible would it be for the valve stem seals to need to bed in? They are, after all, rubber.
  12. Thankyou for all your advise guys.It smokes both when cold and when i start up say after being in the shop for 15 mins.What i have decided is to get the bike the hell out of that shop.I feel regardless of the problem it will be difficult to get a unbiased opininion from the.Especially if they have stuffed up!.I will be looking at getting a second opinion and go from there...thank's again
  13. I'm no mechanic, but I've been screwed by mechanics many times, so I mostly do my own stuff now.

    Some of the useful stuff I've learnt is
    * White smoke is usally water vapor.
    * Blue smoke is usually oil

    If it wasn't there when you dropped it off, and it is there when you you picked it up, then they've screwed something up.
  14. If the smoke goes away after a few minutes, I'd bet my left nut it is NOT pistons and rings, and they will know that damn well. They ARE trying to bullsh*t you so get it to another shop right away and if you're still worried get a compression test done. Any competent mech will be able to determine whether rings or valves without pulling the head off.
    White smoke = water vapour (or possibly some leftover gasket material burning), but may just be condensation.
    Blue smoke = oil, and in bright sunlight it can sometimes look almost white. But if it stops smoking after a few minutes it's usually valves/guides. It's also possible they simply haven't cleaned up the original damage properly.
    Tell 'em NO pistons/rings, and if you can't get them to make good for no extra payment, you probably need to walk away :(
  15. Zackly.

    they havn't seat one of the seals properly on it collet