What is that noise?

gnyce

Site Supporter
Asking for any assistance that can be rendered, as I'm currently striking out. This project (being going on for a bit, I know), a 1990 Yamaha FZR600, has been back on the road and doing well - or so I thought. On a rather uneventful ride - an errand, really, on my birthday - about a mile from home, some God-awful noises started and bike just died.

Long story short, the pressure plate (clutch basket) just disintegrated. No idea why. Dont' believe there was any crazy preceding event. See results below. (bad on left, good on right)


PXL_20211011_211316239.jpg


This was pretty discouraging, as I thought all issues on the bike had been ironed out. So I determine what needs replacing (I have some spare parts from an extra non-running engine), dropped the oil pan to pick out the metal bits, etc - I have it running again. But there is a pretty loud clatter that is new. My assumption is that this was some caused-effect from the birthday incident, but I've been unable to track it down. I did find the main cog in the starter clutch had some bad/uneven teeth, and so I replaced that. No change.

PXL_20211011_211512214.jpg

New clutch plates/springs, different steel plates, swapped clutch baskets, changed needle bearing.... no difference. Starting to wonder if this is indeed a clutch/starter-clutch issue, but it seems most noisy there.

Video below. Open to suggestions, as right now I'm casting about. Here is what it sounds like (below). I'm able to shift, clutch seems to work (bike is on stands), I've gone through 1st/2nd/3rd gear with no issue.

Screenshot 2021-10-11 5.37.53 PM.png

Bike startup
 

Gary in NJ

Junior Member
Site Supporter
Wow, that is a significant noise. Do you access to a stethoscope? It might help you locate the location in the case. To me it sounds like the cam chain (chain hitting the guide). It it could just as easily be the oil pump gear. It’s hard to tell from a video.
 

marke14

running on empty
Elite Member
I do not know about such things but - seriously - I think Gary above may be onto something. To my ear that sound has a distinct "chain" sound to me.

Actually, what it kind of reminded me of is when I have my FZ6 propped up on the rear stand for chain maintenance, and I spin the rear tire with my hand to run the chain around after I've cleaned and lubed it. It has that "tick tick tick" kind of sound to me ...
 

marke14

running on empty
Elite Member
P.S. holy smokes what a meltdown in the clutch basket! One would wonder, did that even precipitate the noise you captured in the video, or was it something else that also destroyed the basket?
 

TownsendsFJR1300

2007 FZ6
Site Supporter
Me thinks something isn't assembled correctly or something got bent and is rubbing currently.
That doesn't sound like a chain noise to me.

Did you find all the pieces, no major chunks un-accounted for?

As noisy as it is, it has to come back apart anyway and I suspect you'll see some "wear" / rubbing marks in the area..


As for why the clutch gave up the ghost, it looks metal fatigue. Previous owners could have ran it real hard and the aluminum finally gave out after years of service.
 

gnyce

Site Supporter
P.S. holy smokes what a meltdown in the clutch basket! One would wonder, did that even precipitate the noise you captured in the video, or was it something else that also destroyed the basket?
I was about 2 miles from home, on a 4-lane highway... blipped the front brake as traffic was backed up b/c of a left-hand turn lane... and bike made kind of a weird noise, almost like a radiator fan was rubbing... but it rose/fell with the engine/throttle. But it wasn't bad. Then was going up a hill, 25-mph/90-degree turns, and crunch-crunch, clutch went slack, bike lost power, stopped. Again, not really much of a preceding event to speak of. Yes, it was quite a shock to find.
 

gnyce

Site Supporter
Me thinks something isn't assembled correctly or something got bent and is rubbing currently.
That doesn't sound like a chain noise to me.

Did you find all the pieces, no major chunks un-accounted for?

As noisy as it is, it has to come back apart anyway and I suspect you'll see some "wear" / rubbing marks in the area..


As for why the clutch gave up the ghost, it looks metal fatigue. Previous owners could have ran it real hard and the aluminum finally gave out after years of service.
I'm thinking the same, Scott - but I might not be looking in the right place (or just not seeing it). Should probably take another look at the starter clutch as well. I've had the clutch cover off 5+ times, trying different approaches. As for pieces... as far as I can tell, I got it all, but sure it's possible I didn't. There _were_ pieces of metal in the oil pan, but nothing too huge. Biggest was about 2/3 of a washer. Gary, I _do_ have a stethoscope, that's a good idea. Will try that tomorrow.

PXL_20211002_170227318.jpg
 

gnyce

Site Supporter
I do not know about such things but - seriously - I think Gary above may be onto something. To my ear that sound has a distinct "chain" sound to me.

Actually, what it kind of reminded me of is when I have my FZ6 propped up on the rear stand for chain maintenance, and I spin the rear tire with my hand to run the chain around after I've cleaned and lubed it. It has that "tick tick tick" kind of sound to me ...
The thing is - if I had no chain issue/noise _before_ the pressure plate exploded - why would I now? It seems to me that either it is 1) something that _caused_ the pressure plate to die (unlikely), 2) something as a _result_ of the pressure plate dying (more likely), or 3) something I missed/is still broken, or re-assembled wrong (also likely). But so far I've been unable to find/address.
 

Gary in NJ

Junior Member
Site Supporter
The thing is - if I had no chain issue/noise _before_ the pressure plate exploded - why would I now?
Because stuff went through the engine. What are the passages like between the clutch side and the main side? Is there an opening where some shrapnel may have made its way through? Perhaps a good engine flush with kerosene is in order.
 

trepetti

It's all good!
Elite Member
Site Supporter
I wonder if this is similar to issues from clutch plates exploding. We have has members that have experienced material being added on the gearset that connects the outer basket to the crank gear. We have seen where the material gets squeezed in the teeth, heats up and bonds to the teeth, causing an interference fit in the gear set.

Take a look to see if there is any new metal on the gears....
 

gnyce

Site Supporter
All good points/ideas
Because stuff went through the engine. What are the passages like between the clutch side and the main side? Is there an opening where some shrapnel may have made its way through? Perhaps a good engine flush with kerosene is in order.
Yup, very good point. Was actually thinking - what if a metal piece made it over into the gears cogs of the transmission. The argument against that is the regularity/consistency of the noise - EDIT - although that just argues against any remaining metal pieces being the noise, as opposed to add'l damage already caused.

I pulled out my cheap stethoscope, and again it _sounds_ like the behind the clutch cover is the "most local" source of the sound. It's not definitive however - noises/vibrations travel well through metal, so I could not swear in court. Will see if I can try any other permutations later this evening.
 
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TownsendsFJR1300

2007 FZ6
Site Supporter
I forgot to suggest, does the noise stop with the clutch pulled in?

Also, if not too big a PIA, peek into the cam chain area, see if any chain guides got damaged and rubbing up against the cam chain.
 

gnyce

Site Supporter
I forgot to suggest, does the noise stop with the clutch pulled in?

Also, if not too big a PIA, peek into the cam chain area, see if any chain guides got damaged and rubbing up against the cam chain.
Nope, no difference at all, clutch in or out. I've been perusing the fzronline.com archives, and there has been some mention of that specific behavior - so far, nothing that exactly matches mine. I'm going to step away for a few days - have some parts on order (gaskets, woodruff key, bearing). Back to looking at starter clutch, though teeth all look regular (stethoscope on far left of clutch-cover was not as loud as far-right of start-clutch cover). I'll try to think of other ways to narrow the sound. I'll be back though and report anything. Thanks for all the suggestions!
 

bigborer

Site Supporter
Not sure if this was mentioned beforehand (too lazy to read all replies) but I'd bet that the previous owner tightened the crap out of the 5 clutch basket screws, elongating and weakening those threaded tubes, which then lasted... until they didn't.
 
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