I noticed a new sounds, ticking, clinking coming from the timing chain area when I am stopped at a light. The sound goes away above idle.

On my M88/3 powered M5, I destroyed an engine when the timing chain guides became brittle after 18 years and broke off. The fragments locked the cam chain and stopped the cams, destroying the entire upper engine.

Expensive lesson to replace timing chain guides on BMW motors after so many years.... However, I imagine the material used for the guides (and the technology of the cam tensioner and geometry of the gears and so forth) is probably very similar on the K100 as it is on my M5.

I am going to pull the front engine case (can it be easily done?) and have a look to see what is happening in there.

Has anyone every had to replace any timing chain components?

This is a very easy job. BMW recommend replacing the chain every 60K. You have to remove the cover and the Hall sensors
One of the 8 holes on each cam shafts sprockets have a notch. Put each notch in line with the valves cover seat, mark the position of the Hall sensors and your good to go. If everything is marked correctly, you won't have to setup your timing/ignition when re-assembling.
To remove the chain tensioner and guides, you just have to pull a couple of clips.
This job can be done in 2 hours (taking the time to clean everything)

I here is a couple of pictures.



Your problem may be as simple as the piston of the chain tensioner gummed up. The engine oil pressure push the piston and it put tension on the chain. Put it apart and clean it as this is a common problem with the old K100 (K75 is the same).


There is a locating pin for the ignition trigger. It can go only one way.

Do you recall the price of the parts required to refresh the timing chain and guides and tensioner?

Thanks!

Hi Scottie,
Take a look at http://www.maxbmwmotorcycles.com or http://www.realoem.com both of them list prices for some parts and can quickly quote you.
Regards,
K-BIKE

Hi, I have just gotten the bike running really well, (87 k100) then I have had some new noise, took off the timing cover and had a look, the guides and all look ok, but looking at the chain itself where it comes of the crank gear, there is a little build up of slack before the chain goes into the top guide if you look at Berts last photo of the crank gear, on mine the top chain is slack, some of the time, is this normal. It sort of jumps tight as the top cam catches and then goes slack again. The piston tensioner work freely.

Brian

yankeeone wrote:The piston tensioner work freely.

If you can push the piston back in the bore, it don`t function properly.

It`s a lock mechanism inside allowing the piston to move out, but not return.



Inge K.

Yes, the tensioner does lock to stop from going back down, but it is clean and free. I see marks on the cover as per Berts rebuild site, so I will put new chain for starters.

About slack between crank gear and top guide, have a look in this link.

Inge K.

awesome link, thanks.

i have a similar issue about the chain slapping round at idle ...especially after a "good run" ,,,but i have purchased a kit from motobins for in the future ...wasn't too "wallet crippling"



good luck yankeeone

Update-- I pulled the timing chain ,but before I did I tried line up the cam gear notches and the crank gear mark,with the locations described in the book, but the crank gear was about a 1/4 inch from the mark with the two cam gears dead on, so when I put the new chain on should I move the crank gear to the mark? also I have a lower guide bar from another bike and the plastic part that the tentioner rides against is a bit wider than present one, so it covers the oil hole in the tentioner, that may have been part of the problem.

Thanks

Brian

yankeeone wrote:, so when I put the new chain on should I move the crank gear to the mark?

I would have aligned it with the factory marks, but be careful so you don`t misjudge something, you did move the crank anticlockwise?

Inge K.

Right, anticlock wise, looking from the front, clockwise looking from the rear, so the chain was tight at the top of the crank gear. that lined up both cam gears with notches up, but the crank gear was a bit beyond the mark, so I may have to retime it, but it seems should set them to the marks as shown in the book , but I will have to wait till I get the new chain on Mon. then see how that lines up.

Thanks

All seemed to go well, the slack on the top of the crank gear is way less, and all the marks line up, the one thing I am worried about is the new crank seal, I put it in after the cover was on and when the lip slid over the crank end the lip or edge is facing out , unlike the old one where the edge is to the inside , but I dont see how I could install the new one that way, with out pushing it in all around ,then it would tear.

Brian

sounds like youve got it in backwards yankeeone



yes it does look like the seal would tear ....but if you have a look at the seal inner you will see that there is a spring along the inside seal ....carefull installation of the cover plate is required ...(like all seals ) use oil or light grease to coat the inner part whilst it is being pryed on .



hope this helps

Thanks, yes the old seal had the spring, but the new one is just one membrane and I think it has to go in the cover first because the lip wont start on the shaft, so I will try again. With a new one.

Brian

Update,all back , new chain, new seal, tricky to install new seal, had to mount it on a small plastic pill container that just fit over the crank end, then it went into the cover tapped in with pvc pipe , then pull out the pill container, that leaves the seal with the lip in (new type seal) . I am now timing the bike the Scotty Sharp method. so far so good.

Brian

good result yankeeone ...nice thinking

Thanks, found the method on the internet. bmwmoa site

Brian

When I replaced my timing chain, all of the plastic guides and front seal earlier in the year, I used a second hand tensioner assembly that looked like it was in better nick (OZ for condition) than the original. Now here we are eight, nine months later and the chain is gravelly sounding. The tensioner has slipped back a notch allowing the chain to run slightly loose. There's enough wear inside its guts to allow it to jump slightly. I bought the last new tensioner assembly in BMW's Melbourne warehouse and am fitting it and a new lower guide this weekend because it copped a good old scoring from the too-loose chain. The bike runs fine, but the noise at idle is a bother.

Now you tell me..

Brian

good luck twb ....i guess you have the oportunity to ride another for the next couple of days and leave "the red streek" at the workshop ?

wouldnt mind seeing the tensioner for real , and lucky it happened close to home ...would have been a regular pain in 3 .9 weeks huh ?

Great tip on the pill bottle Yankee! Was it a name brand available in the generic drug stores?

Thanks,
OG

The one from the mail order blue pills should work...

Well, I wouldn't know anything about those C....really I wouldn't I swear!



OG

I had to look around a bit, the first fit over the crank end ,but would not fit thru the seal, so I took a smaller one and heated it up with a heat gun, when soft I forced it over the crank end let it set, and it fit the seal .there is just room for the thickness of the plastic.I think it was a tylanall (sp) I am up to the age of pain, and close to the age of blue pills.

Oldgoat wrote:Well, I wouldn't know anything about those C....really I wouldn't I swear!



OG

lol you guys ....heheh

good to see you here og ...we've been missing ya mate !

Thanks Yankee for the schooling! I'll have to go in search of the bottles on lunch break! Hopefully, I can work a little magic with the heat gun like you did and I can finally get the front of the motor all sealed up.

Hey Charlie! Yea mate I've just been working my tail off trying to advance the career and had no time for the Bismarck lately. :-( Rob got me set up with some front m/c parts and club c got me those tank tracings and with the crank seal issue still plenty of little projects to do and hopefully I can finally carve out some time this weekend to get after them again.

Have a good one guys!

OG

I forgot to mention that I cut the bottom of the container off , thats the end that goes over the crank end, push the cut end that is heated and fit thru the seal from the out side face then slide over the crank end. I set the seal with a piece of pvc pipe that I was careful to get a nice strait cut on , then tapped the seal flush in the recess, then twisted the container as I pulled it out.

Good Luck
Brian

Here I am on a beaut sunny Sunday arvo, with MotoGP from Motegi's Twin Ring in Japan looming large within an hour or two on the tele, and I'm at the workshop diagnosing a noisy timing chain.

I've just now discovered a timing chain with 64 plates (128 links) inside my motor when it should have 63 (126 links). It's a good thing I have K bike mates round here 'cause Charlie has just opened his Motobins timing chain kit and counted 63 out. He's on his way over to the workshop with it. I'll replace it for him...with one that has 63 links. If you have recently purchased a Motobins kit please count the links and be sure you fit the correct one, unlike me.

The problem was that nine months ago I replaced the chain, but over the past couple of weeks (and fifteen or twenty-odd thousand kilometres) it grew gravelly sounding. To my surprise when pulling off the front cover I could see that the tensioner was well past its useful tension point, cockeyed in its bore, and several mm's past the pin in the ratchet mechanism. I'd even bought a new tensioner from BMW thinking that the old one was perhaps past its use-by date. I'll post a coupla pics later on.

Thanks to the Gods of all things K Bike I will be back on the road this arvo. We do truly get by with a little help from our friends.

This is not so good.


This is very good.

If you note the small circle on the shaft of the tensioner in the first picture you will see that this is the location of the internal pin which seats into the ratchet mechanism BMW employs to disallow the tensioner from returning as the chain 'stretches' over time. This tensioner was at its absolute limit and was merely guiding the chain along its path and on its tippy toes reaching for a kiss from the tall girl at school. It was in danger of falling out of its shoes. The reason was that the owner of the bike fit a chain that was supplied to him by a reputable supplier and did not carefully take note of the number of links. It was two links longer than it should have been and was all right for the time and mileage it covered until it became noisy due to slop and stretch, me thinks, and announced its presence to me.

I am that mechanic, I did the job nine months ago, and take full responsibility for the error. Having been in the biz for many years I don't know how many times I have seen a technician fit a part which was not correct and which subsequently failed and who then asked for some compensation or recourse to warranty. The onus is on the mechanic to be sure it is correct before fitting it. I wince at the idea that this could have been a paying customer's bike. I shudder to think that I could have sent it down the road like this. Always match a replacement part to the part you are replacing. 64 plates does not equal 63.

I put the covers back on, checked all of the fastener's torque settings, gave it a good wipe down, cleaned up my tools then started the bike and listened to the sweet noise of no timing chain noise at all. Today would not have ended so well without our mate Charlie's help.


It's great to finally have a decent workshop and not have to rise up from tired old knees to reach that tool, or fastener or because they've gone crook...


Some of the finer motorbikes that also need a bit of a finesse to bring them back up to snuff sometimes appear in the workshop. Here's a nice, clean '56 R50 with Steib sidecar that our service manager was fettling for a concours d'elegance (gold filligree name for a bike show) coming up in Brissy soon.


Was that a bloody good MotoGP race from Motegi!?

yay !!!!

good technicianing twb ...you saw a problem...asked the question ...sought an answer and ...got the "right" bit

all better now ..!!

cheers

Once again, great write-up TWB...and ya got to love that damned workshop!
Bloody Charlie! Worth his weight in rocking horse manure, isn't he!

I rang in need and he responded, even driving his car down. There's a lot in that. Yep. Rare as these days. Dunno how you repay that.

I suspect Charlie doesn't even think about being repaid; I believe he does it because he gets a kick out of helping people.

Wow TWB a lesson for us all there always check, your so right its so easy to be complacecent and ASSUME all is correct. and three cheers for charlie.



BIG D

Update, all is well ,no leaks, and the timing seems wonderful, it is getting more miles per gallon, down shifting is very smooth due to the instant response to the throttle, and she seems to run cooler with less vibration. I also tracked down a buzz that was driving me nuts, the spring in the right glove box cover holder, put some foam rubber in there and all is quiet.

Thanks for this site

Brian

Good one!

great result yankeeone

Fitted the new chain today; must admit I was counting links like crazy!! Got the 63 one, so good sofar. Pre-tensioned the tensioner, but had the impression it notched one position back, which I thought should not be possible. Got another one here, so better take a good look!!

Hi all, reason for replacing my chain:

nice one rene ....good work !!