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Lwr Case - Is this a crack?

Azdevil09

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Just inspecting and saw this. Not sure if this is a crack. Nothing is visible from the inside of the case. So not sure what’s going on here if if it is any concern.
 

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I'd say the same thing. The process by which these engine cases were cast leaves a lot of "cobweb"-like strings of extra metal inside the cases. When I dropped the oil pan on my own 1980 CB750K I saw the same thing.

If you want to be extra sure, look at it under some magnification and poke it with a pick. It should just be a ridge of extra material above the surface.
 
I would probably agree that it is casing marks. If you want to be absolutely sure then you can use a penetrating dye (like iodine) and see if it bleeds through the casing. Similar to a magna flux to test welds, but much cheaper. You can use most any small molecular liquid (like white gas with a colour added), these have a tendency to bleed through a crack in metal.
 
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