Engine rattle?

[nightwolf0215]

Hi everyone, I just recently purchased my 1991 K75s. After completing most of the services for the bike except coolant change and spline lube, I notice the bike have a rattling noise at about 1800-2200rpm no matter what gear I am in. I've read that this is a pretty common issue with the brick engine, but just want to make sure nothing is off here. What do you guys think?

[Elipten]

Where is the rattle?

[beemuker]

I had a 92 and it didn't have a rattle. I've heard some 4 cyld k's have a rattle at certain rpm's.

[Elipten]

Rear right of engine, it could be monkey nuts in alternator cup

[nightwolf0215]

I can't really tell. Most of the time its ok when cold, but then rattle when the engine warmed up. I'll try to look for the location of the rattle and update for more answer.

Is it anything that might affect safety?

[K1300S]

There are several recent threads with a lot of detail on this issue. ........

[nightwolf0215]

Sorry if I missed a similar thread. I searched through Google and browsed through the forum but haven't found similar situation. Most of the posts I found had some specific circumstances around the bike before it starts rattling.

Anyhow, I rode around this morning to check that noise out and it seems to be coming from the front. More specifically from the gas tank. When I rev to 2000rpm under load, I can feel and hear some rattling from the gas tank. I haven't inspected the tank yet, but no leaks or anything. Previous owner said he paid $700 for a BMW mechanics to get the tank up to speed after 10 year storage. I figured that should mean the tanks in best shape.

What do you think could be the cause of this rattling in the tank?

[Laitch]

What do you think could be the cause of this rattling in the tank?

Posting some audio of the "rattling" might help narrow down the cause. That is what other members have done.

[K1300S]

extensive recent thread.....

http://www.motobrick.com/index.php/topic,7663.0.html