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R100 right side clack

Posted: Wed Mar 02, 2016 6:09 pm
by salty
Hi - I've had this bike for a few months and new to Beemers. It runs smooth, quiet and strong. I got home the other day and put it on it's side stand for a minute while idling.. there was a pretty loud bang and now it makes a pretty horrid noise from the RH side. There is a small change in resistance and if you put load on it the noise gets worse.
I lifted the tappet cover to check if something had let go there but all looked good.
I took a video - if anyone has experienced similar or knows what it could be, would appreciate it.

https://vimeo.com/157503906

Re: R100 right side clack

Posted: Wed Mar 02, 2016 8:26 pm
by dwerbil
How's the engine oil level?

Re: R100 right side clack

Posted: Thu Mar 03, 2016 4:29 am
by SteveD
With the valve cover off, did you check the clearances?

Re: R100 right side clack

Posted: Thu Mar 03, 2016 5:54 pm
by salty
Engine oil is close to full. I didn't check clearances.. but how would they be affected instantly?
I heard a similar noise on youtube and it ended up being a piston sleeve that came loose.

Re: R100 right side clack

Posted: Thu Mar 03, 2016 6:08 pm
by Airbear
Hullo Salty, and welcome aboard.
I can't tell much from the video (slow internet and Vimeo don't get on very well). From the fragment I did hear and your description is appears that something is wrong in there so the next thing to do (after checking valve clearances) is to pull the head and look. Do you have a workshop manual? I find the Clymer is best for it's good pictorial step-by-step descriptions of procedures.

http://www.amazon.com/Clymer-M502-3-Rep ... B000GZX312

Pulling the jugs isn't difficult and can be done with an ordinary set of tools.

Here's a vid on valve adjustment in case you are stumped at this stage. Google will help with other guides.

https://www.youtube.com/watch?v=VExx_2kIc9c

Let's hope there isn't something too expensive in there.

Re: R100 right side clack

Posted: Thu Mar 03, 2016 7:30 pm
by Rob
And measure your valve clearances BEFORE you adjust anything, and write them down in a log.

Get an accurate torque wrench, and check the studs to make sure they are in spec.
Don't go overboard, these studs will pull the block threads in a heartbeat.

When you have determined that stud torque is good, set the valves.

If there are no pieces floating around in the combustion chamber (by removing the heads), put it all back together. Check the valve clearance again after getting the engine up to temp.

Keep a record of the clearances in your new log book.

You want to keep the engine oil level at the halfway point on the dipstick. This gives the engine room to breath. That is more important than "having a lot of oil" in there.

Check the oil level with the dipstick resting on the engine case, not screwed in.

I don't remember the torque values on the studs, (someone here will), but you want to tighten them in 3 steps. And be conservative on the final.

Re: R100 right side clack

Posted: Thu Mar 03, 2016 7:52 pm
by SteveD
Checking the clearances will tell you a few things. It's the first and most accessible place to assess. You've gotta start somewhere.

1. Are they set right, therefore not an issue.
2. If one is very loose, then maybe a stud is loose. Maybe an adjuster has reached a looseness where it's caused a change.
3. If the exhausts are tight, then maybe the seats are receeding.

I was wondering if the noise may have been a backfire or was it more metallic?

If there is nothing wrong with the settings, then you're going further in.

From the video, it looks like a post 9/80 R100. Nikasel bores. It would be a very rare occurrence if the liner came loose. Still, there may only be one way to know.

From the video I think I can hear 3 things. It's traditionally very difficult doing auditory diagnosis like this, but your video is good and clear.
1. Grumbling muffler noise. Noice idle sound.
2. Typical but loud tappet noise.
3. Towards the end a more shrill metallic tinkering noise, with the revving. Might just be tappet noise?

Re: R100 right side clack

Posted: Thu Mar 03, 2016 9:16 pm
by ME 109
Still sounds to be firing on two cylinders.
A seat may have jumped out and been pushed back in by the valve.
Plugs out, in gear a turn engine over with back wheel.
Listen

I'd be pulling the cylinder if I heard bad noises.

Re: R100 right side clack

Posted: Fri Mar 04, 2016 7:39 am
by Kurt in S.A.
ME 109 wrote:Still sounds to be firing on two cylinders.
I wonder how well it's doing that. At idle, the engine is rocking quite a bit...it shouldn't be doing that. I'd say the right cylinder is not working as it should. Investigation can only determine what the problem is.

Kurt in S.A.

Re: R100 right side clack

Posted: Fri Mar 04, 2016 8:56 am
by khittner1
What year do you think your bike is? Assuming that the bike is not a mish-mash of assembled components, its fork and brakes indicate that it's an '81-'84 bike, which would have Nikasil-plated cylinder bores, so there would be no "piston sleeve" to loosen, and one anxiety/expensive possibility would be eliminated.