1981 KZ550 Engine Noise

Hello Everyone,
I have started working on a KZ550 that has sat for about 3 years and has a rather unique engine noise. Before I tear the engine down I thought I would see if anyone has had any experience with such a noise. I have been a diesel engine mechanic for years and my gut feeling is not good, but after reading posts about the primary chain and timing chain sounds I am a bit confused. In my opinion, without having torn it down already, it sounds like it is a spun main bearing. However, the noise only exists from idle to about 2k then the engine sounds fine. I plan to remove the oil filter tomorrow and cut it open to see what kind of yum yums have piled up in there and will report back.
Thank you all for your help!
Russell

Hello, Smarttorque, and WELCOME to KZrider!

Could be cam chain noise. Often significantly reduced by assuring (1) the cam chain tensioner is adjusted and functioning properly, and (2) carbs are correctly synced.

Following links are courtesy of KZr Member loudhvx

General
home.comcast.net/~loudgpz/GPZweb/index.html#home

Service manuals
home.comcast.net/~loudgpz/GPZweb/Mnls/Mnls.html

Good Fortune!

on the KZ 1000....lots of chit likes to sit in pan and dosent make it to the filter. I was shocked the first time mine came off after buying bike.....looked like a cats litter box..... :sick:

Okay guys here is an update. I finally had a chance to pull the oil filter and cut it open. I did find some metal, all aluminum of course, but not as bad as I had expected. At this point, I am going to tear it down because there is really no good reason to have such a "binding" noise. Given the size and quanity of what I saw, the carnage is minimal and hopefully I will be able to salvage the engine. One concern that I had is the primary chain. Does anyone have a good source for them or are they made of "unobtainium"? Thanks for the help and welcome from everyone! I guess I will be riding my KLX400SR for a bit longer this season LOL!

The primary chain is still an "Active" part so any dealer can order it. Ronayers.com lists it at $105. Ed