R100 right side clack

[Duane Ausherman]

Start by doing a lot of reading. Use Google to get related information. You certainly did the right thing by asking before using a hammer.

As a once owner of a BMW franchise with a large service facility, we would consider this an autopsy. Document what you find as you slowly go deeper. Checking and setting valves isn't fixing anything, it is a diagnostic procedure, so do it as suggested. Or, go to http://www.w6rec.com/duane/bmw/valve/index.htm for the method we used.

It is nothing to pull a head and cylinder off. Never use the method of pulling the cylinder part way off and removing the wrist pin to that the piston stays in the cylinder. One must always inspect the piston rings and lands. Use the tool that BMW provides to compress the rings as shown at http://w6rec.com/duane/bmw/piston/ringtool.htm

Be sure to remove the exhaust nut correctly, or you may damage the head. Go to http://w6rec.com/duane/bmw/exhaust/ to get that info.

Take photos at every step. Lay your parts out in the order removed. When you find the source of the noise, it nearly always will be obvious and dramatic.

[ME 109]

Start by doing a lot of reading. Use Google to get related information.

By the time he found something remotely similar worth reading, it could be pulled apart and put back together, with help from questions asked here.

'It went bang, and now sounds not too good'. That's going to take a while, googling and reading.
All the advice would be to pull it down progressively, which he found soon after posting one question here.

[dwerbil]

While on the highway, my '84 RS suddenly started running quite rough, non-stop like a plugged jet on a carb. Ends up it was a stripped valve adjuster nut on the left exhaust valve rocker arm. It could not hold a valve setting. Not much noise involved with this; maybe a close inspection of your rocker arms may come up with a reason for your problem.

[Duane Ausherman]

ME 109, you are right about the time. I have pulled at least a thousand cylinders off, maybe far more and it is so simple and fast. Besides, I like to "take a look" at things. Too often I have found something unrelated to the issue, but needs attention anyway.

Of course we had the spare parts that might be needed, gaskets and exhaust nuts.

[salty]

Hey guys - thanks for the in depth responses.
It's a '81 RT.. pretty original, not a bitsa. It idles well and quiet. This noise happened suddenly, not gradually.
After I heard it I decided to ride up and down the street slowly. It seems under load the noise is enhanced from a loud tappet like noise to something a lot more metallic.. then the power is also affected.. even without adding much load I can tell it isn't happy.
I'm dropping it to BM motorcycles in Ringwood (Vic) on Friday for a diagnosis. I have no problem pulling the engine apart as I have done it many times on my VW fastback.. similar engines.
I'd rather a professional ear hear it before I do the labour - hence the diagnosis booking.

Will let you know what it is and get some advice on the next steps.

[Airbear]

Ah, you're in Melburg, Salty.
I wouldn't be riding it at all. The noise could get a lot more expensive very quickly.
Anyway, here's to a happy outcome.

[SteveD]

Hey salty, I'm in Croydon. 5 minutes from BM motorcycles. Where you from?

[salty]

It's bound to be anyway Charlie

Steve - I'm in Brunswick.

Here's a pic of my bike.. lots to go, will shorten the rear subframe and building under tail exhausts.
I don't run the front fairing much inner city - I like the illusion the bike is shorter in the traffic

[Duane Ausherman]

Please let us know when you find it. From your description, I wouldn't be riding it, just too many expensive possibilities.

Keep asking here at every turn. Just because it looks like a VW, it is a very different animal.

[Airbear]

...
Just because it looks like a VW, it is a very different animal.

Yep, much nicer to play with. None of that fekkin' tinware.

Bike looks very sleek and nimble, Salty. BTW, a mob of us Oz Boxerworkers get together for weekend tech sessions** at comfortable camping spots around Vic and NSW. Your attendance would be welcome - er, once you get your bike running happily. Details in the Motorcycling sub forum.

** Tech sessions may contain little of technical value.