small o ring found while changing cap and rotor what could it have came from?

[VictoryRed]

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[GoToGuy]

O ring or black, finish washer?

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[VictoryRed]

o ring it’s rubber and had grease on it

 

[GoToGuy]

Sure it wasn't just a " Klingon " , slipped in unnoticed?

 

[VictoryRed]

Sure it wasn't just a " Klingon " , slipped in unnoticed?

could be from a tool or something honestly no clue