engine rattles (dead? seizue?) - UPDATED

[ben2go]

So I opened up the left, right and top engine covers and everything looks fine.

1. The cam-chain is taught
2. The shims are in place
3. The generator rotor and magnets are fine.
4. The pickups, rotor and clutch plates looks good.

So everything now points to some spun bearing inside the engine. Some more observations.

1. I have been able to record the engine sound. As I wrote before, it is able to idle but with a loud noise.
http://www.confusionart.com/share/motor.wav (the sound starts at about 5 secs)
2. The bike was *really* low on oil. I had put about a liter of oil after the screwup, and what came out in drain was about 1.3 liters.
3. The oil is blacker than black.

Any other suggestions under the new evidence (sound, oil info)? I have a feeling that changing the engine is my best bet now.

Did yo find any metal particles in the oil you drained, or did the oil look like it had very tiny bits of suspended glitter like metallic paint?

No there were no metal particles in the oil. Not very sure of the suspended glitter - it looks like there is some metallic paint, but its very faint. Definitely not discernable particles. 

Sounds like a spun bearing.The running recording along with silver in the oil that looks like metallic paint,all points to a spun bearing.Did you check the valve to shim clearance?

[GeeP]

You've lost a lower end bearing.  At least one. 

Split the cases and inspect all the bearings and journals.  Also inspect the cylinder bores for wear.  Replace all the bearings at a minimum.  Have the crankshaft and balance shaft ground and fit new undersize bearings.

Also, inspect the transmission bearings and the gear teeth for galling.  Replace gear sets as required.

[yamahonkawazuki]

yup tiem to get greasy  it is fun by the way

[nikux]

Today I unmounted the engine from the frame.

I was in dual minds - one wanting to break it down and replace whats broken, other wanted to save time and effort and install a used one. Lack of experience/help/tools made me go with the second choice: Sell off this engine to someone interested in rebuilding it, buy a used one. Thanks guys for helping me out diagnose the problem, without you help i might have been forced to sell off the complete bike. Now I am just replacing the engine

Btw, if I just get peanuts for the spun bearing engine, I might just as well tear it down to see whats inside...hehehe.... then sell it for peanuts 

[trumpetguy]

One way to look at it:
No one cares about your bike the way you do.  I like to do all my own work for this very reason.  I check everything as I go.  If something isn't right, I stop and make it right before putting it all back together.  Depending on cost (you can check some of this out beforehand) I'd be tempted to rebuild it myself, farming out the machine work of course.

OTOH:
A used GS engine, if running and not noisy, will probably last the life of your bike!  Keep oil in it, keep the valves adjusted, and it will almost go forever.  GS Jack has some gotten obscene longevity from his engines without major work.  I think one of them went 70K miles or something like that.

[cd]

didnt i say to do this a while ago? hahhaha

these motors dont bring much second hand, i would just sell the parts that are worth something overtime or keep it, PROPERLY STORED, hole or in parts, as spares.

i may have a parts motor too, ill see how this parts bike runs, if at all, if not, maybe we could put 2 and 2 together

[sledge]

didnt i say to do this a while ago? hahhaha

That has to be the most patronising comment I have ever read in here.