Gear oil change ?

[RTZ]

Need to change gear oil on my 1987 88hp V4 Evinrude outboard engine. After looking at a parts diagram, I noticed Evinrude shows some different seals / o-rings for the fill plug and vent plug. They show a clear nylon washer and a black rubber o-ring for these plugs. Are both required for each plug? If so what order do they go?
Reason I am asking, I had some water intrusion and notice my fill and vent plugs only had the black o-ring and no clear nylon washer/gasket. I am a bit confused by this since it is not made clear on the drawing or in the manual I have. Any OMC guys out there with an older motor and know what to do. Thanks.

 

[Fed]

Shop evinrude shows them both with the same part number 0333572 described as 0 rings.

 

[racerone]

Older plugs used the nylon washer.----Newer plugs used the o-ring.----The o-ring can be discarded and the washer used on newer plugs as well.

 

[RTZ]

Thank you. I was looking at the diagram and parts list and if you order the plugs they come with the nylon washers, but you can order the o-rings separately. I am going back to the nylon washers, since I believe that is what the engine came with.

 

[Vic.S]

Thank you. I was looking at the diagram and parts list and if you order the plugs they come with the nylon washers, but you can order the o-rings separately. I am going back to the nylon washers, since I believe that is what the engine came with.

I think you will find there screws plugs are slightly different depending on whether the are intended to have O rings or flat washers.
The underside of the heads is flat if they are for the washers but there is a recess to retain the O ring if they are for O rings. Basically it allows the heads to compress the O rings by the right amount before coming up to metal against metal.
There should be no problem fitting washers on either type but O rings should only be fitted to the recessed head type