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sounds like bits of metal going around the engine?

Discussion in 'Technical and Troubleshooting Torque' started by rabbit, Sep 18, 2007.

  1. My gpx has approx 130km on the clock so far, and when its started from cold, I can hear a metallic tinkling kind of noise.

    It sounds like there are bits of metal doing laps of the engine or something. (I have very little knowledge of engine mechanics, sorry) It goes on for a few minutes.

    Its been down to the dealer for a look, but as it was ridden down and warm, the sound wasn't being made. I do plan to leave it overnight at the dealers when time allows.

    Any ideas ?
  2. Cam chain rattle, and a worn engine will take a few secs to get oil pressure up if the oil is thick, and may be a top end rattle until pressure builds.
    With 130km on it, I reckon it would be a bit of a grenade, just ticking away. If it is cam chain, get it done asap, it will be expensive if it lets go....
  3. ^ he's on the money; get thee to a mechanic, pronto!
  4. Rabbit, has the bike only got 130km or 130,000km?

    Assuming 130km as its a 2007?
  5. Good point :oops: :).
  6. If it's that new, then cam chain tensioner is most probable.
  7. It may be normal. This is a really old engine design and Kwaka's are never quiet.

    Still get an expert to check it out.
  8. Its 130km - its a brand new bike and I've only had it for about 2 weeks.

    The mechanic at the kawasaki dealership had a look at it last week, but as it was warm, it didn't make the noise.
  9. cold rattles can be from a cracked piston sounds like a valve head jingling around until it warms up then gos away - if it is a cracked piston i wouldn't go revving it hard as they tend to fly apart at put holes in blocks. Good luck with it
  10. Lol pour water over it its about to explode

    sounds like the engine casing making ting sounds as it heats up.

    Either way who cares if it blows up it under warranty and there problem.
  11. It's a Kawasaki, they had problems with their camchain tensioner engineers from 1975 to 1995!
    Seriously, keep an ear on it, if it gets worse, get it looked at, but don't worry to much, it is a bit of a Kawasaki trait.
    The Kawasaki cam chain tensioners are a spring loaded ratchet system, whhere as the cam chain stretches and the guide blocks wear, the spring applies tension till the ratchet can click to the next stop. In the meantime you have cam chain rattle.
    It is entirely possible with a new engine that it is in between stops and just has to click in. There is a way to force teh tensioner to the next stop, but let it do it for itself.
    I can all but guarantee that by 1500 kms it will not be an issue.

    Regards, Andrew.
  12. So do the kawas chain tensioners not have any oil pressure on them at all?
    If that is the case, wouldn't it only happen at idle or load reverse (ie on off throttle), had a similar tensioning problem on a hillclimb car that was chain driven. Fixed it by rigid mounting and regularly adjusting, obviously not applicable to a timing chain.
  13. No, it happens any time the chain is moving! Idle is most noticeable due to relatively less other engine noises, but a camchain will get noisier at certain revs. The unloaed side of a cam chain, the side travelling back towards the crank, is in a constant state of being loaded/unloaded by resonances and by teh camlobes, which as they pass a valve, tend to try to "flick" teh cam forwards. This creates even more weird loads on the chain.
    You have to imagine, this cam chain is connected to a crankshaft which has harmonic resonances, and is trying to transmit these resonances to the camshafts, which by their design(big bumps on them) also have resonances. So, you can have a cam chain make noise at a couple of rpms at least. This is why modern auto engines have gone to cam belts, it isolates the resonances a lot better, which smooths out the engine a little and decreases noise.
    A cool trick on engines with a cam driven distributor is to put a strobe light on the ignition, and slowly increase revs. If the cam chain or timing belt is loose, you can see the ignition timing jump or scatter around at certain rpms, indicating can chain/belt resonance or looseness.
    Oh, and you can buy manually adjustable cam chain tensioners for many engines, especially some Kawasakis, so your hillclimb car solution does work on cam chains.
    Regards, Andrew.
  14. rabbit
    just had a 2002 zzr250 rebuilt 300klms ago less than 10000 because of cam and glazing issues. and done under warranty even though it was a second hand bike. go kawasaki. it makes the same noise as you are describing. pulled everything apart changed oil even put a stethascope round it not a problem to be found. if you are rideing sunday come over for a listen and happy to check it out for you
  15. These are pretty rattly engines, my old gpx used to make all sorts of wonderful noises when it was cold (tho mine was an 87 model, not an 07 :shock: ). It could just be a trait of the bike. That said keep an eye on it and if you are still concerned once the engine is run in def hassle your dealer bout it.
  16. All GPX/ZZRs 250s I've heard make almost as much noise as a Ducati when they're idling...
  17. just coined a new term for it...Kwakarattle.
    Dictionary entry-
    Kwakarattle, an annoying, rattling cacophony, seemingly unable to be tuned out or solved with replacement parts, but associated with formidable power and reliability.
    Regards, Andrew.