[Matticus]

Hi all, I don't post much but I have no idea what to do with this.
Engines making a horrible rattle/clatter once over 4500rpm, I won't dare rev it any higher than 6000rpm.
It's turning over and idling smoothly but the noise it too scary, I think it's not detrimental but I'm no mechanic.
It seems to be around the cam chain or front of the engine but I can't be sure.
Here's a short vid

zx6r '98 engine noise unknown clatter rattle 5k rpm

youtube.com

Ive had this bike about 8 years, 2 years ago I took it off the road as it started to make this noise and I've been trying to fix it ever since. Its clocked 70k+ miles.

A little background story on it -
2 years after I got the bike the engine developed a rod knock so I replaced it with a similar miled one, that's what's fitted now and had been ok for a good few years but would overheat and cut out now and then, hard to restart.

Carbs have since been cleaned, replaced filters valves and jets etc and diaphragms replaced as they had shrunk. Fuel mix settings are fine and they seem to be well in sync. Then I discovered the tank was leaking and so I went through the whole Kreem scenario. Seemed to work.
I put my big boy pants on and did a valve adjustment too, thinking that's a cause of the hard start. But i fudged up the cam fitting due to some confusion with the manual - I redid the whole job and got it right second time, running ok- in fact it was good and strong,responsive (pow pow)I was really happy...

Soon after, a mate passed his test... as a favour i lent him this one and got a newer bike for myself, I was considering upgrade anyway.

He complained about cutting out still and high temp so I checked again and found melted wiring on the ground runs, fixed. the fan connector had got all crappy causing the overheating.
He filled it with super diesel twice - i'll not rant about that.
We had done a few good trips together and it was ridden most days.
After about 6 months he gives it me back complaining about this clatter noise, no word on how it developed or anything. I've been scratching my head since.

Now I've had it apart again thinking maybe I adjusted valves badly before?
Anyway so they're all checked again and I replaced 4 more shims. Refitted cams and everything correctly, turned over the engine by hand it feels smooth without any clunk's or serious resistance, the cct was clicking into position.

But I get it back outdoors and fire up, still getting this noise.
It's had new plugs, oil and filter.
I've seen posts saying melted plugs could be smashing the piston but it's not that, and nothing in the combustion Chambers.
I thought about loose or tight valves smashing but the gaps seem fine now.

Lots of videos and posts say look at cct so I'd swapped the one from my old engine. After running it seemed to be jammed. I've now reset the thing and refitted it but still getting this noise.

Really no idea what to do besides shopping it but can't afford a mechanic's investigation right now and another engine would be like schrodingers cat. I just want my baby back on the road as I have some stuff to fix on my current horse.

Ideas above what I've tried already would be appreciated
Cheers!

 

[mattv]

If it's the cam chain tensioner, a trick I've seen is to loosen the two bolts holding the tensioner to the motor. This will allow the tensioner to extend out an extra click. Might be a quick and easy thing to try. A manual tensioner would also be an option.

Video of the trick:

One other thing that comes to mind, and might not be relevant to the zx6r, but I think on the zx7r there's a piece of rubber mounted to the underside of the valve cover to prevent the cam chain from slapping against the cover. If that gets chewed up, I imagine you could hear something like this.

 

[Matticus]

Hey, thanks for the quick reply!
To be honest I was trying to do that trick earlier as I've seen a few similar videos. But I couldn't tell if I got a click or not, access to the tensioner is well awkward and I was scared of not hearing it and going too far - no big boy pants this time. However this video gives me more confidence as the guy seems to back it out more than I expect.

If I have time and light in a bit il give it another try, otherwise it's gonna be tomorrow morning.

I don't remember anything in the cover but there is a chain runner that's torqued down with the cam holder, and the chain guides either side all seem in good condition.
If the tensioner reset doesn't work il tear back in to check they arent flopping about and search again for anything being jammed up or loose.

 

[mattv]

You may want to wait a day or two to see what other replies you get, there are some really knowledgeable (much more so than me) people on here, so you'll hopefully get someone with more experience to identify that sound.

 

[92Ninjas]

Sounds like cam chain rattle. As others have mentioned above, you'll need to try to make sure the CCT is working properly. That's where I would start.

 

[ninjanut]

I would not recommend loosening off the mounting bolts as a way of making an adjustment. That is a good way to mess it up big time and why Kawasaki recommends NOT doing exactly that. Once those bolts are loosened, you must reset the tensioner.
The one simple thing to check for that noise is the exhaust studs/ nuts. If they come loose it will sound like what you hear in the video.

 

[Matticus]

Cheers guys, well it now sounds a bit better but still got the noise.

I removed the tensioner, it seemed jammed again about half way out. Reset and checked the thing works normally while not fitted, seemed alright.
Reset and refitted to the bike as per the manual but while turning the middle bolt this time i couldn't feel any clicking.
So I did the click trick to wake up the ratchet. I think the tensioner is probably dying though.
So it fired up alright on choke I kept rpm under 3k allowing a short warm up and tensioning, it sounds fine at idle but Blip over 4500rpm it's clacking still.

I sat down for a bit and went back out to do this video so it had cooled back down, so using some choke and only got a bit of fuel in the carbs. I hold the rpm about 3/4k for a bit then back off the choke, at about 55sec I give a few blips so hopefully it can be heard. Still scared to go over 8k, obviously.

I'm dead sure it's not the exhaust - gaskets, studs and nuts are quite new, all tight and perfectly in line. There was a crack on one of the pipes where they all link inder the simp but i made a really good repair on it years ago. Everything else bolted down solid.
(My other bike is blowing cos I snapped a stud, so I get what you mean)

 

[ninjanut]

If you reset the tensioner as per the manual, why turn the centre bolt? It does not adjust anything. The automatic CCT works off an internal ratchet mechanism. That is simply a cap covering the spring for the ratchet.
If you read the manual it will actually state not to loosen the mounting bolts.

 

[Matticus]

Hey, haynes manual shows a different tensioner so this seems to be the j/a type but meant to be better and compatible, mine is a g model but both tensioners i have are the same.

I remove the tensioner like this,
Middle bolt 12mm first,removing the bolt,washer,spring and pin. Leaving the ratchet exactly where its tensioned to.
Then remove the top and bottom bolts 8mm.
Then give the thing a wiggle and pull out.

While its out in my hand there was no movement in the ratchet even the button bit wouldn't move but a wiggle of the foot part loosened it up. I could then pull it all the way till it stops.
Then I set the ratchet back all the way and push it manually through the the hole the spring and pin would be, click click click...all the way out again.
I do it again with the spring, pin and 12mm fitted,as the bolt tightens up it does the same.
All still in my hands.

So I remove all the spring etc putting them aside. I reset the ratchet to notch 5
I then place the tensioner into the hole it belongs in (the o ring is fine and the ratchet still oily)
Then I fit both 8mm bolts and tighten evenly.
Then i carefully hold the 12mm bolt and washer with the spring and pin, push all together in the middle hole, now pushing on the spring and tighten the bolt up so as it tightens it compresses the spring which then decompresses pushing the foot of the ratchet? Pushing out any slack as the chain comes up from the crank

I know perhaps I should manually turn the engine for the tensioner to reset after removal but it doesn't seem much different right now, I'm not pinning the throttle or riding it.

I'm aware doing the click thing could cause overtightening but there is no obvious sign like whizzing noise, I think it reduced the rattling but its the clatter on the top of any revs that's worrying me.

Il head out soon and do it all again,
This time il try without setting the ratchet and I'll try pushing the ratchet manually before installing the spring etc.
Maybe il turn it by hand too.
If all that fails its back indoors for more head scratching.

 

[92Ninjas]

Hey, haynes manual shows a different tensioner so this seems to be the j/a type but meant to be better and compatible, mine is a g model but both tensioners i have are the same.

I remove the tensioner like this,
Middle bolt 12mm first,removing the bolt,washer,spring and pin. Leaving the ratchet exactly where its tensioned to.
Then remove the top and bottom bolts 8mm.
Then give the thing a wiggle and pull out.

While its out in my hand there was no movement in the ratchet even the button bit wouldn't move but a wiggle of the foot part loosened it up. I could then pull it all the way till it stops.
Then I set the ratchet back all the way and push it manually through the the hole the spring and pin would be, click click click...all the way out again.
I do it again with the spring, pin and 12mm fitted,as the bolt tightens up it does the same.
All still in my hands.

So I remove all the spring etc putting them aside. I reset the ratchet to notch 5
I then place the tensioner into the hole it belongs in (the o ring is fine and the ratchet still oily)
Then I fit both 8mm bolts and tighten evenly.
Then i carefully hold the 12mm bolt and washer with the spring and pin, push all together in the middle hole, now pushing on the spring and tighten the bolt up so as it tightens it compresses the spring which then decompresses pushing the foot of the ratchet? Pushing out any slack as the chain comes up from the crank

I know perhaps I should manually turn the engine for the tensioner to reset after removal but it doesn't seem much different right now, I'm not pinning the throttle or riding it.

I'm aware doing the click thing could cause overtightening but there is no obvious sign like whizzing noise, I think it reduced the rattling but its the clatter on the top of any revs that's worrying me.

Il head out soon and do it all again,
This time il try without setting the ratchet and I'll try pushing the ratchet manually before installing the spring etc.
Maybe il turn it by hand too.
If all that fails its back indoors for more head scratching.

or replace it with a functioning CCT. Though I think ninjanut is critical about the CCT failing. IIRC, I don't think he's seen one fail before. He'll chime in to confirm. I haven't experienced one fail either. So, I'm in the same boat as ninjanut if that's the case. Are all of your CC guides still in place?

There's always the option of replacing it with a manual CCT from a company like APE. I think there's also another company that makes them too.

 

[Matticus]

I can understand the worry but suppose if its dying its dying either way, only running it for a few minutes at a time anyway. The guides looked good when I checked the valves. I have thought about a APE but it could just be a waste.
Anyway i've replaced the cct with the original one again. I set it to no clicks and bolted it in. Used the spring and pin to push the ratchet. I counted 9 clicks, maybe 10, and installed the 12mm and washer nice and tight, didn't notice any more clicks but it does have 19 notches altogether.
Fired up again kept rpm as close to idle trying to be gentle on the warm up. Then build up the revs, no whizzing or whirring (chains not too tight) but it's still clattering.
So I pulled the airbox and did another short video.

cct reset still rattling ninja

youtube.com

But I hear it around the middle to right of the engine. I cant pinpoint but doesn't seem to be anything hitting the valve cover.
Gonna be some more indoor time I suppose, make sure the tensioners doing it,guides in position,timings right and valve holder tight.

Dont wanna but think I need to pull the head...

 

[92Ninjas]

I can understand the worry but suppose if its dying its dying either way, only running it for a few minutes at a time anyway. The guides looked good when I checked the valves. I have thought about a APE but it could just be a waste.
Anyway i've replaced the cct with the original one again. I set it to no clicks and bolted it in. Used the spring and pin to push the ratchet. I counted 9 clicks, maybe 10, and installed the 12mm and washer nice and tight, didn't notice any more clicks but it does have 19 notches altogether.
Fired up again kept rpm as close to idle trying to be gentle on the warm up. Then build up the revs, no whizzing or whirring (chains not too tight) but it's still clattering.
So I pulled the airbox and did another short video.

cct reset still rattling ninja

youtube.com

But I hear it around the middle to right of the engine. I cant pinpoint but doesn't seem to be anything hitting the valve cover.
Gonna be some more indoor time I suppose, make sure the tensioners doing it,guides in position,timings right and valve holder tight.

Dont wanna but think I need to pull the head...

Sounds like either the CC is still loose or maybe something in the valve train. Do you have a mechanic's stethoscope?

Amazon.com: Lisle 52500 Mechanic's Stethoscope : Automotive

Buy Lisle 52500 Mechanic's Stethoscope: Automotive - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

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This will greatly help you narrow it down.

 

[Matticus]

Hey,
I have the cam cover and pusler cover off right now.
Both the guides are in and the chain tight all round
I could barely see it but the cct was extended and pushing the chain. Anyway i set tdc 1/4 and removed the tensioner
It's on 12 clicks
Theres now slack as expected but nothing else has moved, awesome!

So poking at the base of the chain slack through the tiny gap above the crank, windering if i anything can get in there. Then I heard it.
The plastic guide for the slack side bouncing off the inside of the engine, I can see it through the tensioner hole.
So I don't know if the tensioners are both dead and are just plunging in and out constantly. Is that possible with the design?
I'm gonna reinstall with all the covers off and see if I can coax it into working properly, fingers crossed I might be a happy guy tomorrow.
Here's a vid of the racket, think we cracked it?

 

[92Ninjas]

Hey,
I have the cam cover and pusler cover off right now.
Both the guides are in and the chain tight all round
I could barely see it but the cct was extended and pushing the chain. Anyway i set tdc 1/4 and removed the tensioner
It's on 12 clicks
Theres now slack as expected but nothing else has moved, awesome!

So poking at the base of the chain slack through the tiny gap above the crank, windering if i anything can get in there. Then I heard it.
The plastic guide for the slack side bouncing off the inside of the engine, I can see it through the tensioner hole.
So I don't know if the tensioners are both dead and are just plunging in and out constantly. Is that possible with the design?
I'm gonna reinstall with all the covers off and see if I can coax it into working properly, fingers crossed I might be a happy guy tomorrow.
Here's a vid of the racket, think we cracked it?

I think you cracked it! Excellent job. I'm eagerly awaiting the next update. Also, don't mind the vids either.

 

[mattv]

I think you cracked it! Excellent job. I'm eagerly awaiting the next update. Also, don't mind the vids either.

Yeah, I've learned a lot on this one, thanks for posting all the info and videos as you go along.

So I don't know if the tensioners are both dead and are just plunging in and out constantly. Is that possible with the design?

I was thinking this yesterday, but there's conflicting info on these wearing out. I don't see why not, they take a beating, right? Plenty of posts where people have the noise, replace the tensioner, noise goes away. One I saw mentioned it happening right around 5k. There was also info about using 2000+ tensioners in the 98 as an improvement (don't remember what the improvement was, but might be worth looking into).

 

[Matticus]

Really appretiating the input guys
Yeah i guess it does take a beating at up to 19k rpm will have some force could be pushing it back in. Maybe the teeth dont seem worn but the little button bit is, might explain why it seemed to be jammed up too.

So it's back together and a nice day to try.
Fired up and idles well.
3 bars on the temp so gave a few blips and it's happening still around 5k upwards, I held it to around 9k but not made difference. Definately louder on the cam side.
5 bars on the temp and soon the fan kicks in, I'm glad as I fixed the connector.
Clutch and gears work. With no tank or seat i popped it it gear and gently release clutch- no throttle, fighting the stall it does start to drive so I've walked it round the car park without any issue. That's positive at least I suppose there's nothing wrong in the drive train.
I noticed the revs are hanging a bit though, I don't think is an air leak as I always overtighten the inlets. Maybe needs a tweak on the mix screws but i can never work out which way to turn them. Set the same but don't remember the setting.

So I'm gonna try a new tensioner.
Could get a new Kwak one for £95 which will last another 20 years I suppose.
A used one will be a gamble wouldn't it.
So the APE is over £100
Then I found one for about £40 by 'manual tensioner', actually they look pretty good and make them for all bikes. So I might try that first as times are hard.

More update soon I suppose

 

[Matticus]

Oh man what a ballache that MCCT was to fit but I got it there.
Fired up and got warm but still noisy, so I started to adjust, I'm so scared though.
I adjust slowly at idle and eventually could feel the chain vibration against the tensioner, maybe that's enough?

But nope, it's still clattering 😭

I figure maybe it's flapping at rpm still so try carefully adjusting at about 3k (barely any pressure on the spanner) now as its about to clatter I feel the adjuster turns a bit easier for that tiny moment. So I'm pausing to check it doesn't sound tight but it's hard with the racket.

However, now the idle is dropping so I'm adjusting that again. Still sounds OK.
I shut off to think, don't overdo it.
Pop into gear and rock it about. Then start again in neutral.
But now it's slow turning like a really dead battery.

So I back off MCCT again just a little bit and try again. Fired up, I guess it was too tight?

But it's still bloody clattering. It's like on the top of the engine still and down the right side.
I tied a standard stethoscope but it's not helped much. And the fan blowing hot air in my face. Clutch in and out makes no real difference either

So I'm poking around more anyway, then I think..I quite often feel the exhaust on my other bike, if it's blowing well and not full of crap or fuel etc.
So I have a quick go at toasting my hand, it didn't feel like much at idle like barely breathing.
Revving obviously makes it blow more but as it settled back to idle it seemed better. But I'm not sure.
Then I ran out of fuel again and it's bloody hot and doesn't wanna start. Im leaving it to chill for a bit.

Otherwise its back indoors:
Dump oil again,filter for bits.
Remove exhaust check nothings been stuck down it.
Sump off and check for bits.
Goggles on check under/inside for internal damage.
Cams off, remove the head- i expect at least a valve to fall out at this point

 

[Matticus]

Before I do all that though.
I'm thinking about the Reed valves, I know I had them out at some point. Haynes and the kawi diagrams are unclear which way up they go, so could anyone here please clarify scoops up or down?

 

[mattv]

Well that's a bummer. I found a picture of the reed valves that might help: oil in vacuum valve/reed valve- bad gasket?

 

[Matticus]

Thanks, that did help, so I took them out.

They're both stuck to the lids but look the right way using a combo of the pics and diagrams. Its a bit oily in there.
Its bloody noisy without the tubes in, thumb over the hole is quiet. So seems good to me.

Still really nice idle with everything re attached, needle doesn't bob about at all.
Ctc probably was a good shout cos the engine does sound quieter but not eliminated the clattering.
So I'm gonna go for the head soon but UK weather is amazing right now and I'm missing out