I decided i needed to do a few things to freshen up the boat. Motor is a Merc 125hp 2000 model. I drained the lower unit gear oil, do i need to replace the washers on the drain and vent screws? Never have before but have seen some talk about putting new ones on. Also there is a zerk on the steering in front of the motor that i greased and one on the passenger side where the motor up lock is. Are there any more on that engine that i need to grease. Thanks for the info.

I always replace the O rings every time I change the lower unit oil they are not that costly . I bought a dozen of the vent o ring and a dozen of the lower filler plug or screw O ring always have them on hand. I got mine at North Texas Marine. Call first to be sure they have them in stock. You may be able to get them at the Old Fin and Feather on I35 I believe they deal in Mercury.
Tom H

Thanks phototom, any advice on the grease zerks?

In some engine owner manuals it will show where all the grease fittings are.

Don't have a manual. Figured someone would know and chime in.

Just a shot in the dark here. But have googled the engine year,make, and model then choose images. Sometimes you would be surprised at what you can find as far as pictures, schematics, and lay outs. Just trying to help.

Sounds good i will give that a shot. Thanks for your help.

Should be a grease fitting on the swivel bracket also. Very important or bushings will wear out and requires a major amount of work to correct, I had to replace on my motor

I found 4 all together, and greased till grease started to ooz out. I have looked all over that damn thing up and down inside and out and dont see any more so hopefully i got them all. I looked online but didnt find anything on the zerks and location.