Next step for trace amount of something (grease?) on prop

[Cody Stallings]

15 minutes ago, M20Doc said:

I tend to agree with you, that the sludge inside the crankshaft is dirt and lead carried in suspension in the oil, then centrifuged out of the oil.

While I’m no expert I’ve installed more than one propeller over my career, in most cases this is done with an oil change.  If there were no flow of oil other than what is required to fill the prop, how did dirt and lead get into the crankshaft? 
 

Clarence

That’s a great question. Would think the filter would would have caught an dirt and/or Lead.

If there was in fact a continuous oil flow to the props, wonder why the Engine oil isn’t tainted Grey?

As I said above, Your Hands can answer this question.