zxr 400 - rattle between 3-4K revs !!!

[reds]

Hi guys,

Had a fair few issues with my bike recently - got it back in working order, but only thing i cant remedy is the rattle noise i get - it seems to be in 1/2/3rd gear - but only ever between 3.5-4K revs, after that it disappears !

When doing work on the bike i blasted it about the place without the two main fairings on, and the rattle seemed to completly disappear (or was incredibly faint)

However no that I have re-attached the fairings the rattle has come back - I can't see the fairings catching anywhere to cause this - and I am thinking it must be something mechanical as it is always within the same rev range.

The rattle isn't there under engine breaking at the same rev range, and also when it is in neutral and I rev the engine there is no rattle - only when it is moving / in gear.

Any ideas as to what teh cause may be ???

I am thinking maybe cam chain as it is at a specific point on the revs that it kicks in, then goes - BUT - why would the rattle dissapear / get less when the fairings are off the bike ???

Thanks

[yuri2085]

Could you try and track down where the rattle is coming from? Does it happen when the engine is not loaded (in neutral)?

[reds]

no - it only seems to happen when the bike is in gear - when it is in neutral and i rev the engine, no rattle at all

[Vincent]

Take the fairing off again, if the rattle diasappears, you've found your problem. Having said that, it could be that the faring is "catching" the sound and making it sound louder - so double check when the fairings off and make sure it's gone fer sure. If they're not fitted correctly, fairings can rattle and vibrate like good uns.
____________________
Space Is Deep

[reds]

taking fairing off does seem to make it go away - but i think their is still a slight rattle there - and the fairing is amplifying it.

i put the bike up on my paddock stand, and ran it in 1st gear to the 4K mark, where the rattle normally kicks in - however without me physically on the bike - it doesnt make the rattling noise - does this infop shed any more light ???

[extreme3d]

Put a long screwdirver to your ear with the other end on the engine. That will at least tell you if it is engine related.

Have you checked your drive chain tension?

[Noxious89123]

That you can only hear it when moving would point to the drive chain, but being only at certain rpm would point to the cam chain. (Rattle could be caused by the chain or tensioner).

The fairings makes this rather odd, will be watching this thread to see what becomes of it.
____________________
'06 Honda CBR125RW-6 ~ '00 Honda CBR600F-Y ~ '07 Honda CBR600RR-7 ~ Bikeless
'53 Ford Ka 1.3 ~ '03 Vauxhall Astra SRi 1.8 ~ '52 Vauxhall Astra SRi 2.2 ~ '53 Vauxhall Astra GSi

[dougon2wheels]

i had a similar rattle on mine many years ago.....turned out to be the extra baffle in the exhaust system(take the can off and look down the hole!)
later on,i had a rattly cam chain too,but that was higher up the rev range i think,7-8k ish