Author Topic: Suspected Cam/Timing chain chatter (Read 2747 times)

Newb21 · « **on:** 08 April 2017, 04:12:18 pm »

Hi guys,

I'm new here, I've posted in the intro section. Got myself a 98 FZS600 with 16.5k on the clock. Got it late January and have since put over 2k miles on it myself. I've noticed since Monday that once I get above 4.5k RPM I get the telltale clacking sound. Having checked about it seems they can suffer sticky timing chain tensioner. So pulled the carbs, took the tensioner out serviced it and replaced. It seemed that the tensioner was fully extended (took the bolt off the back before removing to check) put it back together and still the same. So pulled the valve cover to check valve clearances. So first question what's in spec for the valves please? Also when the valve cover was off timing chain felt nice and tight but it didn't seem to sit all the way down on the cam sprockets. I could see light between the teeth. Is that normal for the FZS? My experience with DOHC engines s limited and the once I've seen, the timing chain sat right down on the teeth and no light was visible through them

Hope that all makes sense and sorry for the long post

Cheers
Ian

Andy1970 · « **Reply #1 on:** 08 April 2017, 06:00:33 pm »

Hi Ian.

Valve clearances are 0.11-0.20 for the inlet and 0.21-0.30 for the exhaust.

There shouldn't be daylight visible between the cams and the chain. If the chain is loose then it'll ride up the cam sprockets, but it might not tighten fully straight away if you've had the tensioner off. I had mine in bits yesterday and it took a little while for the chain to stop rattling when I put it back together.

Andy.

Newb21 · « **Reply #2 on:** 08 April 2017, 06:27:49 pm »

Cheers Andy,

All valves are well within spec then. Did you have to run the engine for the chain to settle down then? I'm a bit dubious about that since I don't want it skipping a tooth and knocking the valves out.
Also, seen an open ended cam chain with a rivet link anyone have experience with these? I have a chain rivet tool so confident I can secure it sufficiently and it saves the whole tear down & rebuild.

celticdog · « **Reply #3 on:** 08 April 2017, 06:29:57 pm »

Yeah it might not be too bad Ian, One man's rattle is to others is just a tinkle.

Could be a sticking tensioner, take her for a vigorous ride- up to 10 on the revs in low gears should do it.
fingers crossed, otherwise you might have to have a look at the tensioner blades-a loose chain will wear them out rapid.

Newb21 · « **Reply #4 on:** 08 April 2017, 06:50:44 pm »

I see were you're coming from Celticdog its pretty bad though, had a mate who's a mechanic in CMC listen to it and told me to take it off the road straight away. He thought tensioner at first. Hence why I serviced that. But when I had it out and tested it, it seemed to work fine. The other thing that's worrying me slightly is that it seems to bog down about 3k rpm then shoots up to 4.5k with the rattle. I'm thinking this could be because at least 2 carb to head manifolds are split o they're being changed Monday. Ironically I'm studying mechanics in college so I'm pretty good on the tools, but you can never have to much info & help from people with more experience :-)

celticdog · « **Reply #5 on:** 08 April 2017, 07:53:46 pm »

Yeah sounds like somethings not right somewhere

darrsi · « **Reply #6 on:** 08 April 2017, 09:15:16 pm »

I don't remember anyone on here having camchain rattle at such low mileage, and it shouldn't just rattle above 4500rpm, it's normally heard straight away on start up then gradually fades away once the oil warms up, unless it's between clicks then it will remain and sound like a sewing machine.
From memory most people normally get a constant rattle beginning from 25-30,000 miles and above.
Think mine started around the 28,000 mark.

Newb21 · « **Reply #7 on:** 08 April 2017, 09:24:07 pm »

Hi Darssi,
That doesn't fill me with confidence lol. I can't think of anything else it could be. Both me and my biddy have listened to the engine and the noise was coming from the top end. Valve clearances are in spec. And when I took the valve cover off the cam chain wasn't sat in the sprockets properly. I'll change the manifolds and balance the carbs to see if that helps. If not I'll take a video of the sound and post it here.

darrsi · « **Reply #8 on:** 08 April 2017, 09:28:52 pm »

Have a look on YouTube for FZS 600 cam chain noise.
It is normally very noticeable on start up.

Newb21 · « **Reply #9 on:** 22 April 2017, 06:47:42 pm »

Hey guys. Bit of an update. I've replaced the cam chain which was pretty fecked. Did the upside smile when I held it out. Also changed the inlet manifolds and the noise is definitely better & bogging down seems to have eased (can't say for definite as I've not taken for a proper test ride) however I still have a clacking sound between 3-5k. Its not as bad as it was, the worrying thing though. I did an oil & filter change as part of the job & found a gold glitter type sparkle in the old oil. Isn't that a sign that crank bearings are on the wah out? I hope not, shouldn't be on such a low mileage bike!

His Dudeness · « **Reply #10 on:** 22 April 2017, 09:17:35 pm »

Seems very unusual for such a low mileage bike to have these problems. Maybe someone ran it with no oil or something. The old screw driver to the ear trick could help you pinpoint where the sound is coming from.

If the sound gets louder as the oil reaches operating temperature that'd point to possible wear in the big end bearings. Cam chain noise usually is the opposite and gets quieter as the oil heats up. A trick for checking big end bearings is to take out the plugs and rotate the piston to bottom dead center then push a screwdriver down on the piston and feel for movement or a slight clunk sound.

There's a video on youtube of a fazer with worn big end bearings. It's called FZS600 Fazer Engine Rattle. You could compare your noise to that one. Having said all that I think you should bring it to a bike mechanic and let them listen to it.

Newb21 · « **Reply #11 on:** 22 April 2017, 09:21:18 pm »

Awesome cheers dude. Will try that. I'm going to take it to college on Monday. My tutor is motorcycle mechanic with over 20 years experience so will get him to have a listen. Gonna get him to balance the carbs while we're there as well. Heard that can cause a tap/knock sound in one cases as well.

Newb21 · « **Reply #12 on:** 22 April 2017, 09:28:05 pm »

Think I've found the video you mentioned. It does sound very much like mine

darrsi · « **Reply #13 on:** 22 April 2017, 09:38:55 pm »

I was thinking the same as the Dude mentioned, i reckon the bike has been run for whatever reason with too little oil in it at some stage and caused these issues.
At that sort of mileage on the bike it makes no sense to have these problems?

Newb21 · « **Reply #14 on:** 22 April 2017, 09:48:47 pm »

Sounds that way. If its the big ends that's full rebuild isn't it? Balls. My only transport and I've been without it for 2 weeks now already!

darrsi · « **Reply #15 on:** 22 April 2017, 10:23:22 pm »

Persevere with it, it may work out to be very little, you still should have a lot of life in the bike to play with yet.

Newb21 · « **Reply #16 on:** 22 April 2017, 10:43:00 pm »

we'll see. I've given it fresh oil and, new manifolds & cam chain and it does seem better. I'll see Dave on Monday and get his opinion. I'm not experienced enough yet I don't think. Thanks for the help though guys really appreciate it.

darrsi · « **Reply #17 on:** 22 April 2017, 11:51:10 pm »

If looked after these engines are really good, something has happened to yours through neglect from experience.
Once you get to the bottom of it you're gonna have a great bike to play with.
As said, persevere, that sort of mileage is a good'un.

Newb21 · « **Reply #18 on:** 23 April 2017, 07:07:00 am »

Ha! For a minute when Darrsi said to persisting thought he meant just use it as is! Didn't think that was a good idea. I see now he means get it fixed lol

Newb21 · « **Reply #19 on:** 23 April 2017, 07:18:59 am »

OK so had a little look on EBay found some good used cranks if needed but can't seem to find the bearings. I've searched several times with different key words & found 1 set in the USA any ideas where I can pick them up. Just looking at prices etc right now.

darrsi · « **Reply #20 on:** 23 April 2017, 09:13:41 am »

https://www.ajsutton.co.uk/

bikemad · « **Reply #21 on:** 23 April 2017, 09:15:08 am »

I happen to have a complete bottom end if that's of interest to you ?

Newb21 · « **Reply #22 on:** 23 April 2017, 11:38:36 am »

Cheers guys. I'll speak to Dave tomorrow see what he says but if I need replacement parts I'll message you about that bottom end!

bikemad · « **Reply #23 on:** 23 April 2017, 02:00:43 pm »

Quote from: Newb21 on 23 April 2017, 11:38:36 am

Cheers guys. I'll speak to Dave tomorrow see what he says but if I need replacement parts I'll message you about that bottom end!

I'll never use it so I'd prefer someone who needs it or parts gets the use 🙂

Newb21 · « **Reply #24 on:** 23 April 2017, 04:59:34 pm »

Right, another update. Took it over to my dads today as a test ride and second opinion. While we were there, we balanced the carbs, using the guide that was posted on here. On the ride home it seemed a lot smoother than it has since I've owned it. The noise seems to be quieter, it is still there, but as far as I can tell when I get to 65mph-ish it seems to disappear. I'm stumped. Will give you another update once Dave's looked at it to.