I was trying to help a friend change the drive fluid in a pair of OMC Cobra drives. I found the drain screws at the bottom but could not find any side vent screws like on a Mercrusier. I was told the two fat screws on the top surface of the drive will vent and have dipsticks but I was unable to get either of them out. I was also told there are two drain screws in the middle part of the drive and this is where I should fill it from but I was unable to locate any other drains or vents. Do all the Cobra drives have a mid-screw? Can they be filled from the bottom?

you were told right, the flat screws on top are the dip sticks and you will have to get them out, fluid goes all the way up there, as the sticks are only 2" long or so..you can try soaking them in PB Blaster and use a hammer and a chisel to break them loose. the cobras hold about twice the fluid of a merc alpha, and are not bad to do...after you get the plugs out...Rob