Morning team, I took my bike a K100RS to ProCycles at St Peters and cane out with $3750 after they found leaks and all sorts of things which I couldn't argue about but my main problem is riding my bike home I get to 3000 rpm and my engine starts giving off a strange flat vibrating sound, I'm sorry it is hard to describe, I'm going to take a recording of the sound, now today it's a beautiful sunny day and I'm worried about riding my bike in case the sound is something serious, I've called them to let them know i'm bring the bike back tomorrow, until I can add the recorded sound stay away from Pro Cycles at St Peters.

You paid them $3750?

Can you add your bike VIN and year, there are different models ABS 8v and 16v engines.

There is a wealth of knowledge in the group here and lots of folks more than happy to help in exchange for beer tokens.

Im sorry, I have a 1985 BMWK100RS I think it is an 8 Valve engine, I took it back to the work shop and they dont know what it might be, they said it could be the gear box, it went in with no rattling noise on revving up or backing off, I had a new cluck plate installed with this over priced service, the mechanic said maybe because the new clutch plate is in and making connection it maybe causing something else to make that sound.

Record the sound as much as you can, post a video containing the sound on YouTube, and post a link to the YouTube video here.

When it starts making this noise pull the clutch lever in a bit, till it gets firm, and see if the noise goes away. I have a feeling that they may noy have greased the wire ring in the clutch basket.

Rick G wrote:When it starts making this noise pull the clutch lever in a bit, till it gets firm, and see if the noise goes away. I have a feeling that they may noy have greased the wire ring in the clutch basket.

How would that cause a noise? I get that it needs to be lubricated for when the diaphragm spring deflects when the clutch is used but if you're in gear then I don't see how that would cause noise.

I can't offer an explanation but the first time I heard it was a K100 I bought and the next time was when I neglected to lube it when replacing the clutch in my own K100.

That sounds about right to me, I've taken the bike back to them to sort this odd noise out, I dont want to ride the bike in case it causes more damage, thank you for the wise information.

My K100RS 1986 is back with the mechanics who area stumped as to what is making that sound, they are replacing the bearings, thankfully BMW is wearing the cost for this exploration, I just want my bike back without that awful sound, it's very disheartening when there mechanics say they are stumped.

Do they specialise in BMW and certain others? 

When they replaced the clutch the thrust washer might have fallen off and been lost. If they're not familiar with bricks, it would seem that everything is in order. Can they verify the fibre thrust washer was installed on the clutch basket before the clutch basket was installed?

 It should be on the clutch basket when they remove it. With the revs maintained, did the noise disappear with the clutch pulled in?

Maybe the balanced clutch parts weren't put back in their correct orientation, can they verify that? I guess that would be more of a vibration than a sound.  From the factory, there are two white paint marks, and one yellow, they should be spaced 120 degrees apart.

Can you post a video of the sound?