Johnson 90 hp - lower unit oil change - do i need to replace ring washer?

[ib18]

Johnson 90 hp - lower unit oil change - do i need to replace ring washer?
There are 2 screws to take off before lower unit oil change, do I have to replace the 2 ring washers? I know I probably should but do I really have to? if it is not broken why replace or fix?

 

[F_R]

Do they have rubber o-rings? Or plastic washers? If the rubber o-ring type, and they are in good condition, probably ok to re-use. Most people will declare the plastic ones need to be replaced. I suppose for the cheap cost, why chance it? Either way, make sure you get the plugs in tight enough.