Gear Oil Change

Could someone please give me an answer to what is probably a silly question? I recently changed my outdrive oil in my 1998 Hammer 7.4 Bravo One. This is the first time I have done it myself. I read on a thread where this guy thought he might have water in his oil. Someone said to check the O-rings on the drain and vent magnetized plugs. I did not know that there were O-rings on these plugs as I did not see any on mine when I changed my oil. Am I missing O-rings, or do they even have them?
Also, what is chine walking? I'm a newbie, but love this site.
Thanks,
Dan.

TM,
The o-rings sit in a groove on the plug.The o-ring may have stuck to the drive or fell off when you pulled to drain .I would recheck.Chine walking is when rock from side side at higher speeds. ( the boat walks from one chine to the other on the stern of the boat)

[Mbam]

Dan, your drive may not have O rings on the plugs. They were used for a while, but Merc has gone back to the old style fiber washers. Until recently these plugs were black. They usually stick in the housing, and it is hard to tell if one is in there or not. The new ones are orange, so it is obvious if one is present. We make it a rule to always replace them. In most cases if the plug is in place, the fill screw sits pretty flush with the surface.

Checkmate981, I thought the O rings were a great idea but they sometimes tear as the screw is tightened and I guess Merc figured the washers were more reliable.

[boathead]

Check the housing for pieces of the fiber washer, they usually always stick in the counterbore, and don't come out with the plug. I think it's a good idea to change 'em every time you pull the plugs. Also, make sure you use a GL-4 gear oil, not the newer GL-5 rated stuff-it attacks bronze in the upper gear case.
Paul

Thanks guys. That was excellent information and I appreciate your help.
Dan