This isn’t a paint and I doubt a stain. Is this some sort of coating? It’s not on the inside machine surface. What coating is this? Was this done at the factory?
Looks like it wiped off the ball.It's black oxide, and it's not factory.
Edit, didn't see the adjuster. Does it wipe off the adjuster?
Did you wipe it off the ball, or did the pushrod do that?
I don’t know the history on this build. This is what I found on the motor when I opened it.Did you wipe it off the ball, or did the pushrod do that?