impeller change on 1993 40hp evinrude

[nwright]

I am replacing the impeller on my 93 evinrude. the old one did not have an oring the new one does. Do i have to use it. The new impeller does have somewhat of a recess on TOP for what looks like an oring, but i am not sure i need it. I looked at the schematic, and it shows NO o ring being used. Any ideas would be appreciated thanks.

[smarty]

what is your model #. 1993 part shows a 3 blade impeller# 432941. No "o"ring that I can see.smarty