RESOLVED - CG125 Weird Rattling Sound

[veeeffarr]

Hi,

On my CG125, when I am revving it, it makes an odd rattling sound that really doesn't sound very nice at all, it sounds like my keyring vibrating against the handlebars or something (It's not)

I've checked my brake levers and theres a bit of up and down play when I wiggle them, this could be a cause of the problem? Can I tighten these up safely?

I'm at my wits end, it's a really horrible rattling/vibrating sound and it's not filling me with confidence!

Also, don't know whether it's related but sometimes the bike 'lurches' (Just a tiny tiny bit, hardly noticeable)

Is this usual for a CG or should the power delivery be smoother?

Thanks,

Toby R

[veeeffarr]

Bump

[mr.z]

Pick the bike up and shake it arround, if anythings rattleing then it must be somthing daft has come loose.. (if your too weeny get a friend to help )

Is it at all times? certain revs? when its moveing? when its stopped? (if its moveing then check the drivetrain, chain, sprockets e.t.c. even suspension)

It could be almost anything really, short of going arround every bolt theres not much you can do!

If you get a long handled screwdriver and rest it on the engine you can use it to listen to different engine parts.


+ Check your oil level!


Even if you dont think its the keys take all of them off appart from the ignition key then try it.
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[veeeffarr]

[mr.z]

Stick it in neutral, rev it all the way to the top after warming it up, if its not happening then its not the engine..

If so, put it on the centerstand* and then run it up and down second and first gear, checking arround for noises..

I'd guess its your chain, if its loose it may rattle against the case.. when changeing gear its not under as much tension (as far as i understand it)


(*It might be worth secureing it too, something like a ratchet tie from the stand to the front forks, that way it can't come off the stand and go flying into a wall, which does happen all too often)
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[veeeffarr]

[mr.z]

don't suppose you have a pic?? where is it connected to? left side/right side (as your rideing)
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[veeeffarr]

[Slinn84]

sounds very similar to my problem

does it on ratrle when your at a certain rev range? i.e is it fine up until say 6000rpm then the rattle then after it fine again?

cos if so then this is a simple resonance caused by the bike vibrating and loosening something (usually occurs at the point you keep your bike the most, crusing speed for example)

difficult to pin point but try thinking back to when u first noticed the problem, was it just after you took something apart? if so take that thing apart again and re-assemble making sure to tighten everything up properly

[veeeffarr]

I haven't taking anything apart!

So far I have:

Tightened up all bolts around engine
Tightened the 4 bolts that hold the handlebars on
Tightened other bolts around the frame of the bike and checked for loose ones

There is up/down freeplay in my brake/clutch levers, is this normal?

[mr.z]

Yes its normal, they do tend to flap arorund, dont worry about it (put your hand on them when the noise starts, if it stops thats your problem) dont tighten them!

+!!!Be very carefull tightening things without the torque values!!!

Like i said, it is very important when it happens, happening when its stopped or moveing, what rev ranges (or unrelated to the revs)


The screw thing... sounds bizzare, my cg is an older one so can't help you there because theres nothing like that.. the only thing i can imagine it might be is a crude breather valve, any excess pressure pushes it up to let the air out..????? you could try puting some blutack on it holding it open, shouldn't move arround so much then... if the sound stops then its not that.


Wondering one thing.. what revs are you changeing gear?
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[mchaggis]

[veeeffarr]

[veeeffarr]

For future reference this is due to a snapped engine bolt.