Prop play

[Keta-salmon]

In investigating off colored fluid in the lower unit of a 1998 4 stroke Yamaha 50, we noticed, the prop, and shaft can be pushed in, maybe 1/4 inch, and when released will spring back.
Is this by design, as we checked a few of our other yamahas and am not seeing this play.
Thanks

[TownsendsFJR1300]

I've never seen that play, especially "spring" loaded....

[99yam40]

Seems I saw it on my c40 when the wrong thrust washer was sent to me when buying a new prop. it fit but was for a mercury.
they sent me the proper one when I asked about the numbers on it

but could be wrong about the spring loaded part
Has been awhile