Post by: bgcameron on April 09, 2021, 01:12:31 AM
I have a '90 K75S with 53,000 kilometers on it. I am getting a loud, intermittent clacking noise, possibly coming from the front of the engine. It only happens in motion, under a light load at any speed or gear. It seems to happen around 3500 rpm, but it is not a consistent "chatter". It is more like a "clack!...clack clack, clack!". At first I thought it was some noise from the fairings when going over the odd bump. I can even feel it through the handlebars when it happens..
I searched forums and didn't find anyone with a similar issue. It is difficult to isolate exactly where the sound is coming from because it only happens when riding. Help!
Thanks!
Branden
Post by: daveson on April 09, 2021, 05:07:48 AM
A bit of wishful thinking, sometimes it's as simple as a loose spark plug lead, or old plugs or leads. What brand are they?
What about the history, like is it a new problem, or had it for years, or developed suddenly after some repairs, or something like that?
It wouldn't hurt to clean and gap the plugs and leads.
Post by: Laitch on April 09, 2021, 11:06:20 AM
. . . under a light load at any speed or gear. It seems to happen around 3500 rpm . . .If you go full throttle in first or second gear up to 5000 rpm there is no noise?
Post by: bgcameron on April 09, 2021, 12:34:21 PM
I guess that means you can't reproduce it on the centre stand at 3500rpm in gear or neutral. Can you reproduce it while riding at 3500rpm in neutral, or disappears with the clutch pulled in?
A bit of wishful thinking, sometimes it's as simple as a loose spark plug lead, or old plugs or leads. What brand are they?
What about the history, like is it a new problem, or had it for years, or developed suddenly after some repairs, or something like that?
It wouldn't hurt to clean and gap the plugs and leads.
It is so sporadic when riding- I'll be going down a straight stretch of pavement and get a single "CLACK!", sometime more- so it is hard to determine what might mitigate it. I'm sure the problem has existed since i've owned the bike. I have not ridden it much- less than 3000kms. I recently changed the plugs and leads, which did not make any difference.
If you go full throttle in first or second gear up to 5000 rpm there is no noise?No, nothing under full throttle as far as I can tell. Light throttle and maintaining a speed seems to do it.
Is it possible that I have a failing cam chain tensioner?
Post by: The Mighty Gryphon on April 09, 2021, 12:53:43 PM
Post by: daveson on April 09, 2021, 04:44:08 PM
Post by: Laitch on April 09, 2021, 05:38:29 PM
Post by: rbm on April 09, 2021, 09:18:44 PM
Post by: bgcameron on April 10, 2021, 12:08:26 AM
I've checked everything for looseness and no luck. I am going to see if I can replicate the sound with it in gear and on the center stand. I'll check those monkey nuts too.. does anyone have a video/audio clip of the sound it makes when they are bad?
Post by: daveson on April 10, 2021, 04:43:10 AM
Post by: Laitch on April 10, 2021, 08:15:48 AM
https://www.youtube.com/watch?v=i4xJqmm5D6I&t=25s
Post by: bgcameron on April 10, 2021, 02:49:04 PM
Post by: Martin on April 10, 2021, 04:28:59 PM
Regards Martin.
Post by: bgcameron on April 10, 2021, 07:55:48 PM
https://www.youtube.com/watch?v=TVWlJaD7aXA
And I am not sure if this is related but it can be heard at idle.
https://www.youtube.com/watch?v=WuRXtWAVLug
Post by: Laitch on April 10, 2021, 08:26:52 PM
In a previous thread, you noticed "movement of the tensioner" during valve clearance inspection. Does that mean there was slack taken up during rotation of the camshaft? Do you know approximate number of kilometers this engine has traveled and if it has been conscientiously maintained?
Will the engine create that sound when the moto is run on the center stand in neutral at 3500rpm or does it need to be under load?
Post by: bgcameron on April 10, 2021, 08:46:21 PM
Regarding the tensioner, if I remember correctly- there was some slight movement if you were to turn the cams in either direction. I seem to recall the tensioner taking up the slack when turning the cams the correct way.
The bike has 53,000 kms and the for the first 45,000 or so it may have been somewhat neglected. The last owner seemed to be on top of things and did a number of maintenance tasks during his short time of owning it.
I was able to slightly recreate the sound on the center stand , in 1st gear with the brake applied. Now for some confusion- I just had it out and I was going up a slight hill. It did its noise at 3500. I pulled the clutch and held the revs at 3500 and the noise continued to a lesser degree.
Post by: Laitch on April 10, 2021, 11:39:49 PM
If that won't pinpoint the source, you might need to fall back to using my favorite method—ear plug wearing, until the sound gets loud enough to track or goes away. How's the oil level?
Post by: bgcameron on April 11, 2021, 12:42:15 AM
Is it possible that it's pinging? I'm doubtful because of the cool temperatures and light engine load, but at this point I am open to the possibility!
Post by: daveson on April 11, 2021, 12:52:49 AM
"it seems louder on the left side"
That reminds me a bit of the clicking sound when a spark jumps on the outside, although it doesn't seem to effect the revs. Maybe remove the spark plug cover and look for any sparks, especially if it's night time.
Post by: Laitch on April 11, 2021, 09:14:31 AM
Is it possible that it's pinging?That's why trying to listen to action within the case was recommend, before removing the cover. :thisplacewhack
Post by: The Mighty Gryphon on April 11, 2021, 12:49:35 PM
Post by: bgcameron on April 11, 2021, 07:25:32 PM
(https://fotobucket.site/uploads/1375779532d145dc418c28691506a74245532de5.jpg)
Post by: daveson on April 11, 2021, 08:18:33 PM
Post by: bgcameron on April 11, 2021, 08:24:27 PM
Anyway have you ever had the rocker cover off? There's spose to be a spring pressing against it to provide a path for earth.Yes, it is in place.
Post by: daveson on April 11, 2021, 08:44:30 PM
Post by: bgcameron on April 11, 2021, 08:53:21 PM
I spose you didn't find any stray sparks from the leads behind the plug cover or coil cover in the dark?No sir, not yet anyways. Once I have the alternator back in with new bushings then I will report back to you.
Post by: bgcameron on April 14, 2021, 06:44:32 PM
https://www.youtube.com/watch?v=43gnHAfMQH4
Post by: Laitch on April 14, 2021, 08:09:47 PM
That's all I've got. Maybe somebody else will chime in.
Post by: The Mighty Gryphon on April 14, 2021, 10:15:58 PM
Post by: daveson on April 15, 2021, 06:51:23 AM
Post by: The Mighty Gryphon on April 15, 2021, 10:47:02 AM
BMW offers little guidance on when to replace a timing chain. If the tensioner doesn't look worn and the oil passage is clear, you could always replace the chain. Sometimes they last over 100K miles or more; sometimes they stretch sooner.
I replaced the chain on one of my bikes at 108,000 miles. These chains aren't long enough to show a lot of stretch that can easily be measured, the wear evidences as "side curve". I checked it by stretching the chain out and and then bending it into an sweeping curve on a flat surface. It's been a while, but I think a new chain has a depth of about 1/2-3/4" to the curve. The old chain I replaced was close to 2". The side bend play could possibly allow the chain to slap around and hit the case, especially if the tensioner isn't working properly.
If the tensioner has been allowing the chain to slap around for a long time I wouldn't be surprised if the chain is worn. It's one of those situations where the wear accelerates more wear.
As far as the case slapping, have you seen any metal in the old oil? Since the cases are aluminum it won't be magnetic.
Post by: Laitch on April 15, 2021, 01:21:56 PM
Post by: bgcameron on April 15, 2021, 03:01:48 PM
Post by: Laitch on April 15, 2021, 05:45:20 PM
Post by: The Mighty Gryphon on April 15, 2021, 07:02:21 PM
Post by: bgcameron on April 15, 2021, 08:56:14 PM
Post by: bgcameron on April 16, 2021, 12:47:48 PM
Post by: The Mighty Gryphon on April 16, 2021, 01:39:26 PM
The Prestone stuff does a good job on the whole system, but you might have to run two flushes if the scale is really bad. The vinegar does a good job of cleaning out the inside of the radiator as well as softening up the bugs that are jammed into the fins so they can be flushed out with a good rinse.
Post by: daveson on April 16, 2021, 10:35:29 PM
Are there any tell tale signs like black tracking marks where sparks might be jumping?
Now that you found a way to reproduce the sound while the bike is stationary, you might be able to use a screwdriver to pinpoint the source more closely.
Post by: bgcameron on April 17, 2021, 01:56:25 AM
Just double checking before the rocker cover goes back on, does the spring make good bare metal contact?Well she's all buttoned up now, but I did check the spring and its contact area and everything looked good. I am going to run it tomorrow and see what I can find out.
Are there any tell tale signs like black tracking marks where sparks might be jumping?
Now that you found a way to reproduce the sound while the bike is stationary, you might be able to use a screwdriver to pinpoint the source more closely.
Post by: bgcameron on April 19, 2021, 12:59:33 AM
I am at the point now of taking it in to get it looked at. Normally I am more ambitious to fix these things myself.. but my dad passed away yesterday and I just want to take it easy for a while and not stress about my stress-relieving machine.
Post by: daveson on April 19, 2021, 04:02:20 AM
I'd call this noise a non urgent problem. I recon you can just ride for a while and have another look sometime down the road.
Post by: The Mighty Gryphon on April 19, 2021, 08:46:14 AM
My advice on the bike is to just go and ride it. My K75 has rattled at various rpm with an assortment of clanking noises since the day I got her. 45,000 miles later she still runs great and does 7-800 miles days at 85mph with aplomb.
You have checked it out and mechanically it looks okay. Do a thorough service, then put some miles on it and enjoy it.
Post by: Laitch on April 19, 2021, 09:15:57 AM
The clutch seems to make a bit of a clack noise when you are letting it out to get moving, so maybe it is related.If the clutch clacks when the clutch hand lever is released, the clutch arm is likely to be hitting the muffler. If that is the case, the arm could also rattle against the muffler at certain vibrations. It is no cause for worry and a few millimeters of adjustment will stop the rattle.
Post by: daveson on April 19, 2021, 09:44:34 AM
Next time you do a clutch lube, it would be a simple matter to check for output shaft endfloat, and look for balance marks for the clutch.
Post by: The Mighty Gryphon on April 19, 2021, 10:28:54 AM
A simple test(do it after correctly adjusting the clutch) is to pull the clutch lever all the way in, and then let it snap out. Do you hear a clank down by the muffler? Do this a couple times. If you hear it clank, take up a little bit of cable slack with the adjuster at the lever. Only take up a tiny bit and check again for the clank. It should only take a couple mm to stop it.
Outside of this minor adjustment, refer to my advice above.
Post by: bgcameron on April 19, 2021, 04:00:35 PM
Post by: The Mighty Gryphon on April 19, 2021, 08:02:22 PM
Post by: Laitch on April 19, 2021, 10:51:40 PM
I am at the point now of taking it in to get it looked at.I've listened to both your videos. I hear a slight rattle at 12:00 and 18:00. It seems to happen when you accelerate a little. It is so slight that its power to distract you is incomprehensible to me. It's as far from a clack as it is from a quack. All I can come up with is that you're riding at revs that are too low for the gear. Bricks will rattle a little when that happens.
As suggested, earplugs—and shifting at higher revs—are the remedies; the earplugs also preserve your hearing from being damaged by high frequency noise, too. I always wear this reusable, flanged style. Several companies manufacture them.
Post by: The Mighty Gryphon on April 20, 2021, 08:18:59 AM
DSCN1758.JPG (46.82 kB . 768x576 - viewed 733 times)If you like you can tear down your engine to confirm it. My bike has made an awful clank at low rpm and under heavy load when I don't downshift enough since I got it 6 years and 45,000 miles ago. Despite the noise it has run like a bear and taken me across country 3 times since I got it.
I've found that keeping the revs up and wearing earplugs has made our time together much less stressful. It also helps a lot to keep your valve clearances as close to each other as possible as well as close balancing the throttle bodies.
Post by: bgcameron on April 20, 2021, 10:24:58 AM
Post by: Laitch on April 20, 2021, 10:48:01 AM
I am not sure that is the issue I am having though.Then enjoy the hunt! Let us know what it is, how much it cost you to find out and the remedy. Maybe someday, despite everything, you'll ride the moto only to enjoy its g-forces and the scenery flowing past you. icon_cheers That will be challenging. :laughing4-giggles:
I wish you peace during this difficult time for you.
Post by: daveson on April 21, 2021, 08:39:16 AM
A few more desperate maybe's. If the noise is louder with the fuel cap opened, have a bit of a look, maybe a filter or hose tapping against the tank, or pump.
You might have two different noises, one about idle and one at ~3,500rpm. If you pull the clutch in about half an inch (or as much as you can without letting it slip) check if the noise at revs then disappears.
Maybe with a screwdriver to help, check for a healthy click from the injectors, timing light in synch with plugs, headers. Gear box and stuff. Granted it's desperate, but easy checks
Post by: Laitch on April 21, 2021, 09:48:30 AM
Post by: bgcameron on April 23, 2021, 01:02:55 AM
Going up a slight hill, when I heard the rattle I pulled in the clutch and held the RPM around 3500 with the throttle. The noise persisted until the bike slowed down to under 20km/h or so.
I figure this should either narrow it down or do the opposite!
Post by: daveson on April 23, 2021, 08:55:11 AM
Post by: bgcameron on April 23, 2021, 11:45:19 AM
You could also call it a tappet noise. Did you check the valve clearances when you had the valve cover off? You might have some excessive gap/s.
The valve clearance is all within spec.
Post by: Laitch on April 23, 2021, 03:22:00 PM
Post by: daveson on April 23, 2021, 07:24:54 PM
A bit of biffo never killed anyone
(excluding fatalities)
Post by: bgcameron on April 23, 2021, 10:19:10 PM
Your latest description characterizes it as something other than an engine noise, bg. As long as it doesn't start telling you to strip in public or ride to Victoria wearing a loincloth and carrying spear to storm the Parliament Buildings, I think you're OK.
Nobody would bat an eye in downtown Victoria!
I am confident now that it isn't the engine.. I am wondering if it is something to do with the clutch. Whatever it is, it is certainly loud. Cruising on the highway between 3500 and 4000 rpm it is just a consistent rattling sound.
Post by: Laitch on April 23, 2021, 11:06:28 PM
Post by: bgcameron on April 23, 2021, 11:51:32 PM
Record the noise under the new conditions you're describing. If you can't find a recording device that will accommodate a microphone with a long cord so you can affix the microphone on the frame, get a friend and have the friend drive next to you operating a boom microphone close to the frame near the intermediate housing while you perform your novel noise propagation technique with the moto. Nobody will bat an eye. Post the video.
Here is a better video clip of the noise. Don't ask me how I did it haha. The sound is clearly heard at about the 24 second mark.
https://www.youtube.com/watch?v=47n3G3m4HSU
Post by: daveson on April 24, 2021, 05:58:41 AM
Where was the microphone?
Did you try with the clutch pulled in a small amount (putting pressure on the clutch basket) to see if it eliminates the sound, or changes it?
Good work on this recording.
Post by: Laitch on April 24, 2021, 09:33:27 AM
Here is a better video clip of the noise. Don't ask me how I did it haha.Instead of being coy, explain how you did it so somebody else who has a similar noise sensitivity can risk life and limb to record it for the benefit of others who want to identify it. :laughing4-giggles:
I have some questions.
Did you remove the timing chain guide rail and inspect within it for wear?
Did you remove the slide rail and inspect within it for wear?
Did you remove remove both the chain tensioner and tensioner strap to inspect them for grooves and other signs of wear?
Did you remove the tensioner plunger (pedestal) housing and the plunger itself to examine the condition of the assembly?
Post by: bgcameron on April 24, 2021, 11:07:00 AM
Clutch pulled in, noise continues. Laitch, when the cover was off i checked all those components as you mentioned. Everything looked fine.
Post by: Laitch on April 24, 2021, 11:33:36 AM
Post by: Laitch on April 24, 2021, 11:44:48 AM
i checked all those components as you mentioned. Everything looked fine.Does that mean you removed all those components and inspected them? While you're thinking of things to keep from enjoying the ride, check all the exhaust manifold bolts for tightness when the engine is cold.
Post by: bgcameron on April 24, 2021, 02:31:13 PM
Does that mean you removed all those components and inspected them? While you're thinking of things to keep from enjoying the ride, check all the exhaust manifold bolts for tightness when the engine is cold.
I removed everything. The bike has 53,000 kilometers on it. It is a local bike and I am the third owner.
Post by: Laitch on April 24, 2021, 02:55:13 PM
Post by: daveson on April 24, 2021, 07:25:59 PM
I'd almost punt it could be a worn annular spring between the driven gear and idle gea, or shim. Is there a thread with this problem that has sound? In this case I'd just wear earplugs, mind you I wear earplugs without this sound.
Could you post photos of the bike and instrument cluster? Any signs the mileage isn't genuine?
Post by: bgcameron on April 24, 2021, 09:14:29 PM
Do you have this regardless of the engine being warm or cold?
I'd almost punt it could be a worn annular spring between the driven gear and idle gea, or shim. Is there a thread with this problem that has sound? In this case I'd just wear earplugs, mind you I wear earplugs without this sound.
Could you post photos of the bike and instrument cluster? Any signs the mileage isn't genuine?
It seems to happen regardless of temperature. I have no doubt that the mileage is genuine.
Post by: daveson on April 25, 2021, 03:24:54 AM
Anyway I'm curious, in Canada are bricks European (i.e. rest of world?) spec. or US? In the US bricks have miles on cluster and no light switch on the right handlebar. In Australia bricks have kilometers and a light switch. Does yours?
Post by: bgcameron on April 25, 2021, 04:50:33 AM
Why are you confident it's genuine? There's a fair few threads with the plastic cogs broken, they're like thirty years old, most of mine were wonky.Local bike. The original owner didn't ride it much and the bike sat in storage for at least a few years. The 2nd owner didn't own it for long. The odometer reading between the first and second sale ads only changed slightly.
Anyway I'm curious, in Canada are bricks European (i.e. rest of world?) spec. or US? In the US bricks have miles on cluster and no light switch on the right handlebar. In Australia bricks have kilometers and a light switch. Does yours?
I believe this it is essentially the same as a US spec bike, but with a km/h cluster.
Post by: daveson on April 25, 2021, 06:09:05 AM
What maintenance history do you know of?
Post by: The Mighty Gryphon on April 25, 2021, 08:06:09 AM
53,000km/30,000mi is barely broken in. Sitting around unused sticks the pintles in the injectors and the rings in the pistons. I'm surprised it runs. All that engine needs is a couple thousand miles of 4000+rpm yeehaw to loosen things up. Buy some friggin' earplugs and ride the damn thing. You've checked everything and can't find any problems so go and ride it.
Post by: bgcameron on April 25, 2021, 08:25:09 AM
So no light switch but km cluster? Dunno if that's normal for Canadica. How's about photos.Some internet sleuthing revealed some maintenance history! See the article about splines. Hopefully this link works. If not, I will try to fix it later when I am not posting from my phone.
What maintenance history do you know of?
https://www.google.com/url?sa=t&source=web&rct=j&url=http://static1.1.sqspcdn.com/static/f/760327/10120680/1294422490340/Beemer-Reader-17-09-September-2007.pdf%3Ftoken%3DmUfDhk4UT6LaBs50vL3N690JJFQ%253D&ved=2ahUKEwjV96nysJnwAhWyPH0KHWRFDQQQFjABegQIDhAC&usg=AOvVaw2SZu79ToCsVdlJfSTOSxyh
Post by: The Mighty Gryphon on April 25, 2021, 08:45:37 AM
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If your splines are okay, and they should be after a mere 53,000km, then throw a little lube on them and ride the damn bike.
When you put the drive shaft back in after you do the lube, make sure it's locked into the transmission output shaft.
Post by: bgcameron on April 25, 2021, 10:49:40 AM
How's about photos.
(https://fotobucket.site/uploads/48b52181cc0def1cb4ac7347ebb16db39874689d.jpg)
Post by: The Mighty Gryphon on April 25, 2021, 12:00:48 PM
Post by: Laitch on April 25, 2021, 12:08:07 PM
Post by: daveson on April 25, 2021, 05:24:40 PM
How's about the instrument cluster.
Hopefully, as has been said, just needs the cobwebs shaken out of it.
Post by: bgcameron on April 25, 2021, 05:54:16 PM
That's absabloodylutely spotless, I should have known.
How's about the instrument cluster.
Hopefully, as has been said, just needs the cobwebs shaken out of it.
(https://fotobucket.site/uploads/68b6b8849609c3407d260ac20756c05735160017.jpg)
You've got a gen-u-ine BMW comfort seat there, bg. They aren't common but get much better reviews for long distance riding than the OEM bench seats. 112350
It's actually a reupholstered Corbin. It looks very similar to the comfort seat.
Post by: Laitch on April 25, 2021, 06:13:06 PM
It's actually a reupholstered Corbin.:nono2: We'll need to see its papers. If it was a Corbin, it wasn't reupholstered; it was stuffed. :laughing4-giggles:
Post by: daveson on April 25, 2021, 06:42:40 PM
Since you don't have many posts, l looked at them for photos without luck, but noticed at least one valve out of spec. Over max for exhaust, surprising, dunno if you fixed it.
Anyways, it wants a full service and a lot of Kay's.
If you still have the noise, could it be something stupid like a loose air box vibrating? I was chasing a knock in the back of my car once, eventually, eventually I fixed it after emptying the crap out of the trunk. Then repacked it.
Another thing, the annular spring has been under compression for thirty years, regardless of the mileage, it may have lost some tension by now, with the result of a rattly idler gear. Big deal, you don't need an idle gear, you could throw it in the bin (it's only there to reduce noise, if rattly only increases noise.)
Post by: bgcameron on April 25, 2021, 07:08:26 PM
I've been in touch with a local gentleman who has been riding a K75 since he bought it new in the mid 90's. He's offered some guidance on servicing and thought that the clutch splines are worth looking at.
Is the rattling idle gear the one that tends to make a bit of a zipper type of sound with abrupt revs from idle?
Post by: daveson on April 26, 2021, 12:22:40 AM
How's about a video.
I spose the air box idea was wishful thinking on my part, I forgot the handlebar vibrating symptom.
Post by: bgcameron on April 26, 2021, 12:49:13 AM
It may be a matter of simply retorquing a the clutch housing retaining nut.
Post by: daveson on April 26, 2021, 06:27:16 AM
So probably not a good idea to turf the idle gear in the bin, I forgot about its oil gallery, not that it'll come to that anyway.
What an incredible example of attention to detail by BMW, this oil gallery is. It can only rotate a small amount on its shaft, between two teeth of the driven gear.
Post by: bgcameron on April 26, 2021, 06:39:54 AM
That's why I asked if pressure on the clutch changes the sound, but it didn't, making me back away from the idea.
So probably not a good idea to turf the idle gear in the bin, I forgot about its oil gallery.
Perhaps there is still slight contact between the clutch plates that is enough to agitate that gear in the balance shaft. Regardless, I should do a full spline service anyways and torque that nut while I am in there.
Post by: daveson on April 26, 2021, 07:27:13 AM
While you're there, check that the balance marks are in the right place. There was a thread where an unbalanced clutch caused a noise, but not vibration, surprisingly, maybe since the output/balance shaft turns in the opposite direction to the crankshaft.
Post by: daveson on April 27, 2021, 11:04:43 PM
I've added more reasons to your link above.
I think with the crank cover removed you have a small window of access to the driven gear. Probably only useful to check for slop between the drive gear and driven gear pointing to reduced tension from the annular gear. Unlikely, but easy to check for. If there was any endfloat with the key off, you'd think the noise would be at all rpm ranges.
Please chime in if you think this is crap, it could well be, I don't want to waste anyone's time.
Post by: daveson on April 28, 2021, 03:13:47 AM
Post by: bgcameron on April 29, 2021, 04:48:56 PM
Post by: daveson on April 29, 2021, 04:55:27 PM
Unfortunately there's no clutch in the starter.
Post by: rbm on April 29, 2021, 05:07:05 PM
Post by: daveson on April 29, 2021, 05:17:33 PM
Post by: bgcameron on April 29, 2021, 08:11:10 PM
Post by: daveson on April 29, 2021, 08:59:41 PM
If he means the starter is turning the clutch, I'd remove power to it (and insulate) and see if the noise disappears.
Post by: Laitch on April 29, 2021, 09:13:25 PM
He thinks it's the starter clutch.:popcorm
Post by: daveson on April 29, 2021, 09:26:53 PM
Post by: rbm on April 29, 2021, 09:28:10 PM
Post by: daveson on April 29, 2021, 09:38:26 PM
its an easy thing to try.
Post by: bgcameron on April 30, 2021, 01:34:50 AM
What work are you planning on doing? Opening the engine? That's a big job. I'd do some tests first to confirm it's the problem before doing that. Has the starter been working normally, does it sometimes slip? The crank could release the clutch, hard to imagine it could engage it.
If he means the starter is turning the clutch, I'd remove power to it (and insulate) and see if the noise disappears.
I am doubtful that it's the starter clutch.. The starter functions as it should. I am going to to the spline service as planned, torque the nut and hope for the best! Hopefully will get around to it next week.. lots on my plate right now.
Post by: daveson on April 30, 2021, 02:57:06 AM
I'll be keeping an eye out for the result.
Post by: daveson on April 30, 2021, 08:23:21 AM
Just a stab in the dark.
Post by: bgcameron on April 30, 2021, 11:42:36 AM
I've just cast an optic nerve over the video of the timing chain. Any thoughts out there about the timing marks looking to be a little bit out?
Just a stab in the dark.
I think it's the angle of the video. Look at how the holes in the gears align with the base of the camshaft caps.
Post by: daveson on April 30, 2021, 05:47:53 PM
That dog don't hunt.
Post by: bgcameron on May 02, 2021, 03:14:38 AM
Post by: daveson on May 02, 2021, 03:39:09 AM
Post by: daveson on May 02, 2021, 03:47:38 AM
Straining an optic nerve further still.
That black plastic thingy between the steel backing of the chain guide and the tensioner; is that cracked? That's what it looks like to me. If so, could that increase the oil flow and reduce the oil pressure?
Apologies if this is yet another crap shoot.
Post by: bgcameron on May 02, 2021, 04:02:49 AM
Post by: daveson on May 02, 2021, 04:22:33 AM
Have a zoom at it.
Post by: bgcameron on May 02, 2021, 04:33:38 AM
Post by: daveson on May 02, 2021, 04:40:03 AM
Zoom in where the tensioner contacts the backing of the chain guide. Looks like a bit of plastic to eliminate steel to steel contact.
I can't zoom when I press play, but in play mode the right half moves up and down. I'm more confident about it after I zoomed in.
Post by: daveson on May 02, 2021, 04:42:19 AM
Did you check the black bit on the back?
Post by: bgcameron on May 02, 2021, 04:56:21 AM
Oh dear :( I really don't want to take that timing cover off again..
Post by: daveson on May 02, 2021, 05:11:14 AM
It's easy access, especially compared to taking the output shaft out.
To me the video shows movement on the right hand side, like its come away from the guides backing, but that's with a small phone screen.
Post by: bgcameron on May 02, 2021, 05:20:00 AM
Mine's rigid plastic like.
It's easy access, especially compared to taking the output shaft out.
To me the video shows movement on the right hand side, like its come away from the guides backing, but that's with a small phone screen.
Perhaps I'll take a look during my next coolant change, which may happen soon because the water pump appears to be leaking from the weep hole. Speaking of leaks- it's leaking gas too.. not much, but there is some corrosion in the bottom left seam of the tank.
I'm tempted to send the bike out for a buoyancy test.
Post by: Laitch on May 02, 2021, 07:47:37 AM
I'm tempted to send the bike out for a buoyancy test.:popcorm
Post by: daveson on May 02, 2021, 08:22:26 AM
Maybe try the screwdriver sound test on the timing chain cover, about where the tensioner is, with sudden revs from a helper, and the other conditions.
If you gradually increase revs over 3,500 rpm, does the noise remain, or gradually reduce, or suddenly disappear?
Watchyagot.
Post by: bgcameron on May 02, 2021, 09:10:51 AM
https://www.youtube.com/watch?v=HfDR3tkR8C0
Post by: daveson on May 02, 2021, 09:33:58 AM
I ask because if it disappears, that might be at a point where the oil pressure finally reaches a high enough point for the tensioner to work properly.
Watchyagot.
Post by: The Mighty Gryphon on May 02, 2021, 12:26:38 PM
Post by: bgcameron on May 02, 2021, 12:35:30 PM
God! I'm loving this thread! :popcormIts turning into a bit of a Saga.
Post by: daveson on May 02, 2021, 01:32:02 PM
Post by: bgcameron on May 02, 2021, 02:02:14 PM
How's about the noise remaining or disappearing, gradually or suddenly, at some point after your noise at 3,500rpm?
I ask because if it disappears, that might be at a point where the oil pressure finally reaches a high enough point for the tensioner to work properly.
Watchyagot.
The noise seems more sudden. Here's another sound clip. The noise starts kicking in at about 15 seconds. Towards the end I pulled the clutch lever and held revs.
https://www.youtube.com/watch?v=Abu6FVNiNlM
Post by: Laitch on May 02, 2021, 04:05:39 PM
Post by: bgcameron on May 02, 2021, 05:12:12 PM
Post by: daveson on May 02, 2021, 06:10:55 PM
If it's broke, replace it, if your lucky the noise will be gone.
Its turning into a bit of a Saga.
That's not a saga.
I've seen a thread that was longer than War and Peace, that's right and I'll say it again too, it was longer than War and Peace. There was a noise from the water pump and cylinder four so the engine was opened and the output shaft came out. All sorts of measurements were made, and heaps of parts replaced with new. After it was all stitched up, the noise remained the same.
That's a saga.
Post by: bgcameron on May 02, 2021, 06:33:11 PM
Post by: daveson on May 02, 2021, 06:56:29 PM
Post by: Laitch on May 02, 2021, 07:00:12 PM
Thanks Laitch.:popcorm
Post by: bgcameron on May 02, 2021, 10:35:58 PM
Would you say the sound changes or disappears over a certain rpm, if so when?
It seems to disappear after 4000 rpm.
Post by: daveson on May 03, 2021, 02:53:25 AM
Post by: Laitch on May 03, 2021, 09:00:05 AM
. . . even if it ain't broke, might need replacing due to wear.:tinhat2:
Post by: The Mighty Gryphon on May 03, 2021, 09:42:48 AM
Post by: Laitch on May 03, 2021, 10:13:37 AM
Post by: daveson on May 03, 2021, 11:45:59 AM
Why the tin hat? The reference from Colin Carpenter also says it might need replacing if worn.
Post by: Laitch on May 03, 2021, 03:22:52 PM
If I had these symptoms on my bike and that part of the chain guide was broken or worn, I would just replace the chain guide.bg has asserted that everything in that timing chain case has been inspected right down to the molecular level by bg's own eyes, and everything is OK. icon_cheers
Post by: bgcameron on May 03, 2021, 03:34:06 PM
Post by: daveson on May 03, 2021, 07:36:41 PM
True, I didn't notice wear on mine until after I read the link, and If that piece is broken it may, or may not, have anything to do with the noise, but wants to be replaced anyway.
Bg you won't have to eat your shorts either way. At this point there's still a lot of options, for example it's not surprising it's not worn, it's low mileage, but it's thirty years old. The bonding may have partially failed after you looked at it, while installing, say while the guide rail was clipped to its steel backing, or clipping the tensioner on, and cracked later.
When I zoom in I see a black line between two pieces, with the video I see hinged movement on the right side.
Bg, look at the video on full screen and ask yourself this question "does it look like one piece solidly bonded to its backing?" Show this video to anyone and ask them if it looks like mine (please don't ask them if the timing marks align)
To me it definitely doesn't look like mine. If I'm wrong I won't have to apologise because I already did, so there.
I'm hoping I'm right because that's an easy fix.
Post by: Laitch on May 03, 2021, 08:47:27 PM
If I'm wrong I won't have to apologise because I already did, so there.Maybe you should step up like bg and eat your shorts, too. It could be a Zoom event, and posting a link to it here would relieve the tedium. bg's getting adept at video. :popcorm
Post by: daveson on May 03, 2021, 10:20:56 PM
This chip is on the same side as your video, maybe it's just a chip we see.
Post by: daveson on May 07, 2021, 05:02:58 PM
Post by: daveson on May 08, 2021, 04:16:11 AM
It's the circlip.
It could be fatigued or partially unseated from its groove, weakening its effectiveness. Your symptoms are a snug fit for this, I think.
Here's the good bit, since your there anyway, with the clutch basket removed you have a small window of view to see if the circlip is fully engaged in its groove, all the way around.
Here's an even better bit, with the seal removed you have access to the circlip, without having to split the engine.
That circlip has been under constant compression for thirty years, it could be fatigued.
The K75 does not have a diaphragm spring, like the K100 does. The side load from the gears, with their helical cut teeth, would put the circlip under substantial compression in emergency braking situations. The K100 has a diaphragm spring to bear that load, which would be stronger. With the K75 that compression could partially dislodge the circlip. I would guess though, it would be more likely to be fatigued after years of accelerating and braking forces.
I would take a photo of the circlip, then check that it makes contact with the bearing and see if it can be pressed further into its groove. I feel that it will make contact but might not at 3,500rpm.
If your able to speak with the previous owners, it would be worth asking about its service history, and maybe if there were any occasions of emergency braking.
If I was that far in there anyway, I would replace the circlip.
It's not the only possible cause of output shaft endfloat, but I think it's an easy access option.
Post by: alabrew on May 08, 2021, 11:16:10 AM
Post by: bgcameron on May 08, 2021, 03:13:40 PM
Hey Branden, here is something to consider while the gear box is off. This is my guess, hopefully my last guess.
It's the circlip.
It could be fatigued or partially unseated from its groove, weakening its effectiveness. Your symptoms are a snug fit for this, I think.
Here's the good bit, since your there anyway, with the clutch basket removed you have a small window of view to see if the circlip is fully engaged in its groove, all the way around.
Here's an even better bit, with the seal removed you have access to the circlip, without having to split the engine.
That circlip has been under constant compression for thirty years, it could be fatigued.
The K75 does not have a diaphragm spring, like the K100 does. The side load from the gears, with their helical cut teeth, would put the circlip under substantial compression in emergency braking situations. The K100 has a diaphragm spring to bear that load, which would be stronger. With the K75 that compression could partially dislodge the circlip. I would guess though, it would be more likely to be fatigued after years of accelerating and braking forces.
I would take a photo of the circlip, then check that it makes contact with the bearing and see if it can be pressed further into its groove. I feel that it will make contact but might not at 3,500rpm.
If your able to speak with the previous owners, it would be worth asking about its service history, and maybe if there were any occasions of emergency braking.
If I was that far in there anyway, I would replace the circlip.
It's not the only possible cause of output shaft endfloat, but I think it's an easy access option.
Doesn't the K75 have flat drive/driven gears? Without removing the seal, I was able to look around the edge of the circlip. I used an angled pick to reach the holes in the circlip and verify that they are snug.
Post by: daveson on May 08, 2021, 05:51:40 PM
So ignore the side load comments. Still, let's say the circlip is fatigued from 30 years of compression, like I said I'll guess it's still snug. A weak spring could be OK while the engine is stopped or at idle, but could fail at 3,500rpm.
I mention this because you're only a seal away from access to the circlip.
I'm 99% sure this comment doesn't apply to you, but to anyone who has a brick with a rattle, an unknown service history and has removed the clutch basket, you should check that the circlip has been installed with the concave side facing the bearing. It's only the slightest bit concave and could be easily missed.
Post by: bgcameron on May 08, 2021, 07:04:50 PM
Post by: Laitch on May 08, 2021, 07:22:01 PM
Here's an acceptable way to apply it.
https://www.youtube.com/watch?v=87FfDU5r640
Post by: daveson on May 09, 2021, 05:52:17 AM
It's only a 60 second check.
Post by: The Mighty Gryphon on May 09, 2021, 07:23:40 AM
While it's apart, pull the pistons and rods to make sure you aren't getting any piston slap and that the big end bearings are in spec. I'm guessing that you will find all is well, but it might give you some peace of mind.
Post by: daveson on May 09, 2021, 07:54:34 AM
It would be interesting if someone gets to the bottom of it.
The biggest bonus for me with this thread so far, this is the first time I actually heard it (the later video, post 61)
Post by: Laitch on May 09, 2021, 09:05:40 AM
Put your finger through the hole for the starter, wiggle the idler gear, see if you can move it forward and back with its shaft, you shouldn't be able to, unless the spring is broken.If the gear could be wiggled on the shaft, wouldn't that be accompanied by audible Clicks?
Post by: daveson on May 09, 2021, 09:10:45 AM
You know what, in that post the sensible part of my brain defeated the biffo part of my brain, which wanted to say "if there's any axial movement there whatsoever, it's because the spring has been under constant compression for thirty years"
Post by: Laitch on May 09, 2021, 09:14:26 AM
. . .it was louder than I thought, I spose it's about time I learned how to post videos.Louder than you thought, or louder than you expected? Did you check it for rattle after you replaced the spring?
Go to YouTube. Instructions for posting videos are there, then you post the link here.
Post by: daveson on May 09, 2021, 09:32:32 AM
I meant it was a lot louder than I expected,more than a quack, probably deserves the honour of a clatter, dare I say a knock.
I wonder if the noise would have been louder if the microphone was taped to the starter motor? It's on the left hand side, that's the side that was originally thought to be louder.
Post by: Laitch on May 09, 2021, 10:36:42 AM
I meant it was a lot louder than I expected,more than a quack . . .Was that more than the volume of a startled quack, a courtship quack, a maternal quack, a quack in flight or a quack on a still pond in early morning?
Post by: daveson on May 09, 2021, 06:27:56 PM
Post by: bgcameron on May 09, 2021, 07:48:34 PM
It was desperately loud, like the sound of an African duck attempting to cross the Mediterranean with a coconut tied to its testicles.
Who are you, who are so wise in the ways of science?
I checked that gear for movement and felt nothing...nadda.. Ni!
Post by: daveson on May 09, 2021, 07:59:33 PM
One of the jokes lost on young ones watching it now was the intermission. Back in the days you couldn't expect people to remain seated for two hours in a cinema. I remember when the intermission sign came up, people started making their way along the aisle, suddenly the movie started again, and everyone rushed back to their seats.
It's good you have no movement there, it's not easy to replace if Faulty.
Post by: Laitch on May 10, 2021, 10:17:16 AM
. . . it's not easy to replace if Faulty.Faulty Towers?
Post by: daveson on May 10, 2021, 04:26:30 PM
I've noticed that attention to detail is one of the items in your tool box. I've been thinking to myself, I should try that. As you can see from this thread, I need more practice with it.
Post by: daveson on May 10, 2021, 07:27:49 PM
Did your brick come with a workshop manual/s and which?
Post by: bgcameron on May 10, 2021, 07:38:34 PM
Can you tell us about any non routine work done on your brick, mechanical, cosmetic, anything? Anything by previous owners?
Did your brick come with a workshop manual/s and which?
The only thing I know of is the Bruno-modded rear drive. Speaking of that- in the article I linked to a few pages back, the original owner said that the U-joint mod was done.. but there is no serviceable U-joint on this driveshaft.
Post by: daveson on May 10, 2021, 07:53:23 PM
Post by: bgcameron on May 10, 2021, 08:07:46 PM
Where the frame bolts to the intermediate housing, do you have a shim between the two? I believe you should have.
Yessir.
I just spoke with the original owner of the bike. He purchased it new in 1990. It sounds like most of the its mileage was done on the highway. He is going to dig up his service history on the bike and send it to me.
Post by: daveson on May 10, 2021, 08:18:11 PM
I'm running out of useful suggestions, in case you haven't noticed.
The original owner could be the key to this. I'd ask if he noticed this noise, if it developed gradually or suddenly, or anything about it. You might be able to link it to something in the service history.
Post by: Laitch on May 10, 2021, 11:17:45 PM
OK, it's hard to find fault with a low mileage brick that looks absabloodylutely spotless.It didn't seem that hard for bg. :laughing4-giggles:
Post by: daveson on May 11, 2021, 06:59:49 AM
Where I was going with the previous posts was hoping the frame was removed for painting or something, and not installed correctly. Although that possibility is almost eliminated, it might help someone in the future reading this.
If the frame is attached using the Clymer manual as a guide, the shim location and bolt tightening sequence will be wrong, since the k75 sequence is different to the one given.
Hopefully Gryph might chime in again, at least I'd be interested to know if his noise sounds like your recording.
Gryph, help me out here. Your saying ride, free up the rings, get fuel through the injectors, shake the cobwebs out. Yep, I'm with you there, you know I'm with you there, but your well ridden brick does it too. I'm trying to get something that fits, it's like almost there, but just not there yet.
Post by: Laitch on May 11, 2021, 07:55:36 AM
. . . the original owner said that the U-joint mod was done.. but there is no serviceable U-joint on this driveshaft.If there is no zerk, the guy's a jerk, to paraphrase Johnny Cochran. :laughing4-giggles:
Post by: Laitch on May 11, 2021, 08:15:30 AM
Until you get the service history, maybe try . . . an Italian tune or something like that.I suggest La Primavera by Vivaldi. It's the perfect time of year for that. 112350
Post by: daveson on May 11, 2021, 08:35:42 AM
Post by: bgcameron on May 13, 2021, 01:41:40 PM
Bike is back together and the noise is nearly gone. Under the same riding conditions it will make the occasional "tap" sound but nothing in comparison to the clatter that was audible before. My best guess is that culprit was the nut on the balance shaft.
Post by: Laitch on May 13, 2021, 01:53:44 PM
I did the disassembly today. Nothing appears to be out of the ordinary. All the splines are well-lubed, the U-joint feels good. The clutch housing nut seems tight, and it did not move under 100 ft-lbs of torque.From your post, it appears like you did nothing to the nut because the nut seemed tight. Maybe the cure was just the laying on of hands. I've seen that work miracles in venues as disparate as fundamentalist churches and South Dade honkey-tonks. :laughing4-giggles:My best guess is that culprit was the nut on the balance shaft.
Post by: The Mighty Gryphon on May 13, 2021, 02:15:57 PM
Post by: bgcameron on May 13, 2021, 02:55:52 PM
From your post, it appears like you did nothing to the nut because the nut seemed tight. Maybe the cure was just the laying on of hands. I've seen that work miracles in venues as disparate as fundamentalist churches and South Dade honkey-tonks. :laughing4-giggles:I forgot to mention that I replaced the nut and o-ring while I was in there. I gave the new nut just over 100ft lbs of torque.
Post by: The Mighty Gryphon on May 13, 2021, 04:43:43 PM
I forgot to mention that I replaced the nut and o-ring while I was in there. I gave the new nut just over 100ft lbs of torque.
Okay, if you go back to post #49 in this thread and look at the photo, you will see that the two parts are pulled together by the clutch nut. When you tightened it, you increased the pressure holding the faces together so they are more difficult to move relative to each other and make the tang clank in the slot.
It's nice that you have reduced the noise, but be aware that some time in the future, the friction between those parts will decrease enough to allow your noise to return. I hope that by that time you are able to ignore it and just ride the bike. It won't hurt anything.
Post by: bgcameron on May 13, 2021, 05:06:55 PM
I could not accept a clatter as loud as what my bike had. Hard for me to ignore.
Post by: daveson on May 13, 2021, 05:19:40 PM
I'll also guess the clutch nut is on a little tighter, a nut on a bit under 100 might not move cause it takes a bit more to get going.
So it's not eliminated but way better, good. The next rider with these symptoms who is removing the clutch basket has an easy opportunity to see if replacing the circlip eliminates the problem.
Gryph help me out here, the balance shaft isn't doing much more than driving the pump, could the forces overcome 100 ft/lb on the clutch nut? And if so, why don't all k75's do it? And at 3,500 rpm? And the machine marks are still on yours? I'll have to say this again, I'm not a mechanic and this is over my head, but I think a new circlip MIGHT solve it, and it's easy to get to. I hope this doesn't come across as pushy, just trying to get to the bottom of it.
I spose someone will give the circlip a try in the future.
Branden, just curious, the clamped cuts in the old clutch nut, I spose they were closed?
Post by: The Mighty Gryphon on May 13, 2021, 06:41:33 PM
Post by: daveson on May 13, 2021, 07:19:40 PM
I think the clutch nut and circlip both contribute to eliminating endfloat. Let's look at the drawing and imagine the circlip totally fatigued, not just partially. It is so fatigued that there is a gap, between the circlip and bearing, even with the engine stopped. That would be worse again, possibly with a knock at all rev ranges. In that case you would still have a knock even with the clutch nut at 150 ft/lb.
On the occasion that the noise remained after pulling the clutch in, until it got to 20km/h, that again points to the circlip, I think. Pulling the clutch in compresses an already weakened circlip. In the video I think I hear the noise momentarily between gears when the clutch is pulled in. That was why I asked earlier about pulling the clutch without disengaging it, since it only happened under load.
There's a service bulletin relating to the earlier version about output shaft noise, due to, amongst other things, a loss of pressure applied by an idler gear diaphragm spring. The minimum action recommended, was that it be replaced. In the newer version, it's replaced with shims, pressure is applied on the bearing by the circlip. That also makes me think that replacing the circlip could be a fix, and can be replaced without splitting the engine, so that's one good thing.
Post by: bgcameron on May 14, 2021, 02:05:31 AM
Bonus, good work.Yes, they were closed.
I'll also guess the clutch nut is on a little tighter, a nut on a bit under 100 might not move cause it takes a bit more to get going.
So it's not eliminated but way better, good. The next rider with these symptoms who is removing the clutch basket has an easy opportunity to see if replacing the circlip eliminates the problem.
Gryph help me out here, the balance shaft isn't doing much more than driving the pump, could the forces overcome 100 ft/lb on the clutch nut? And if so, why don't all k75's do it? And at 3,500 rpm? And the machine marks are still on yours? I'll have to say this again, I'm not a mechanic and this is over my head, but I think a new circlip MIGHT solve it, and it's easy to get to. I hope this doesn't come across as pushy, just trying to get to the bottom of it.
I spose someone will give the circlip a try in the future.
Branden, just curious, the clamped cuts in the old clutch nut, I spose they were closed?
Perhaps the noise wasn't caused by the clutch nut at all. As Laitch said, "laying hands on it".. perhaps there is something between the engine and the rear wheel that tends to get cocked somehow and it gets fixed in the process of a simple spline lube.
Gryph, I may be a little OCD but I am not a defeatist. It would be silly for me to sell such a gem of a bike. These machines are rare around here and I've got enough mechanical aptitude to keep it running. Did you listen to my last two recordings of the noise? I was really hoping you would chime in and let us know if this is similar to what your bike was doing.
Throughout this process of the teardown there is a tool that I borrowed from the 30-year/370,000 km K75 owner that was extremely helpful. He took scissor jack and welded a plate to match the holes on the bottom of the gearbox where the center stand attaches. There are a couple of skids on the bottom to keep it from tipping over. This made removal and installation of the gearbox incredibly easy!
(https://fotobucket.site/uploads/870c65cdec2749dc5fcdbbb8a085b1e9f83bd61e.jpg)
Post by: daveson on May 28, 2021, 10:02:46 PM
Post by: daveson on February 13, 2022, 08:30:51 PM