Crud in the Oil

Carveacre

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1981 XS650SH stored in a damp shed for 28 years. My previous thread was Got it Back. I changed the oil and filters, and scraped some crud that looks like broken pieces of black plastic off the small filter. Nothing on the sump filter. What could this crud be? With the new oil and filters in, I plan on stroking the engine 10 strokes with the kick starter every day for the week or so I am derusting the gas tank and cleaning the carburetors. Will it be safe to try starting the engine? It strokes freely with no noise with the spark plugs out. Thanks for your concern and your good advice. Carveacre in CA
 

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Here on the right are the bits that I found at the sump filter. When I opened up the motor, the lining was completely detached from the guide (the parts in the picture) and the cam chain started to carve into the aluminum body of the front guide. These is a lot of discussion about this issue on the forum as the guide is a common failure in these bikes with age.
 

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This is the sound you’ll hear if all of the plastic comes off of the tensioner foot. That and you’ll about run out of adjustment. Until then, run it.
I would not run it. Just imagine larger pieces getting into the chain at the crank sprocket. I do confirm this noise as a sign that something was wrong and I did run around with it for a couple of months
 
My 78 sounded fine but I could tell my cam chain was stretched cause I was at the end of my timing adjustment on the points. Pulled it open to change cam chain and look at the front guide and change it while I was in there only to find the plastic totally de laminated. I could not hear anything wrong at the time.
before pulling it apart I had a few little plastic bits in my fuel filter and like yours (and many of us) the sump filter was blow in.

https://www.xs650.com/threads/1978-xs650-special-project.65053/page-13
 
I would not run it. Just imagine larger pieces getting into the chain at the crank sprocket. I do confirm this noise as a sign that something was wrong and I did run around with it for a couple of months
Mine shed a lot of plastic off the edges. The chain was still running on plastic. The engine in my video shed the plastic completely.
 
You can even avoid breaking the cam chain by sliding off cam shaft bearings for a minimally invasive fix. That said, why not replace the cam chain while you all the way in there anyway. Also not sure how the base gasket is going to continue to seal with the pressure taken off and retightened.

Yes, the cylinder head must come off.
 
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