OMC Cobra Stern Drive drain plug...uh-oh

[Master Mate Mike]

Hey all

I have a 1987 Sea Sprite with the OMC Cobra stern drive. Like another post I've read on here, I also opened the drain plug that used to be hidden by the Cobra badge on my OMC Stern drive.

Needless to say, the retaining nut ker-plopped into the stern drive housing.

So....if anyone out there can pity dummy me (wasn't my fault...supposed to be a badge covering it and why does the plug have a screwdriver groove if it isn't supposed to be opened anyways???) and let me know the easiest and most painless way to extract it (maybe thru the water pump cavity!?), I
would be much obliged and promise to never open another plug for the rest of my life.

Many thanks and kind regards to all,
Mike

 

[Don S]

Re: OMC Cobra Stern Drive drain plug...uh-oh

Remove the outdrive, tip it upside down, roll it around, tip it side to side until you can get it into the proper position, then put the screw back in with some red locktite on the threads and tighten it up.

It's not a drain screw for anything, it's just a screw that holds a plate in place. WHY you ask? Good question that no one actually knows the answer to. Best I have see is that the plate is actually a wear plate in the cavity where water tends to erode the housing the most. While it sounds good, no one really knows and it may just be there to coverup an engeneers mistake.

 

[Gary H NC]

Re: OMC Cobra Stern Drive drain plug...uh-oh

And don't feel bad,hundreds of people have made the same mistake

Happy wrenching! Good time to service the ujoints while its apart too..

 

[HT32BSX115]

Re: OMC Cobra Stern Drive drain plug...uh-oh

Yeah....plenty of people have made that "second mistake" removing that "plug"

Mine had the "Badge" missing and I have the service manual so I didn't remove it. I learned later that it shouldn't be removed before I did anything to the drive. I would have removed it otherwise......being the umpteenth person to make that mistake.......I hate when I do that!

Good thing is, you didn't hurt anything and no parts fell anyplace where they could hurt anything...


Cheers,

Rick

 

[whywhyzed]

Re: OMC Cobra Stern Drive drain plug...uh-oh

Yeah....plenty of people have made that "second mistake"

took me a minute

 

[flabum]

Re: OMC Cobra Stern Drive drain plug...uh-oh

Then fill the screw slot with JB Weld so it won't happen again

 

[Master Mate Mike]

Re: OMC Cobra Stern Drive drain plug...uh-oh

Guys

Many thanks for the tips and the attempts to reassure me that
I'm not the only "curious" person out there.

I love some of your posts!!!

Ok......let me psyche myself up and hunker down and do this...

Happy New Year to all!!!!

Mike

 

[Lou C]

Re: OMC Cobra Stern Drive drain plug...uh-oh

Those parts are not even referenced in the earlier parts books, not until 1992, before that the only thing that was referenced was the Cobra medallion. Mine never had the medallions on it, on one side there is the normal screw, on the other is a rubber plug that fits perfectly, if I knew what size it was and where to get it I'd post it!
As long as we are discussing Cobra quirks, make sure that when you refill the gear oil, you do it the OMC way, which is different than the Merc way. You have to drain from the bottom most screw on the lower, with the dipstick on the top cover removed. Then replace the drain screw, and place the dipstick in the top cover but don't screw it in yet. Next you fill it from the screw that is on the lower unit, but up near the foward end of the anti-ventilation plate. Pump slowly to avoid getting an air bubble in there. You need to get 64 oz (for the regular Cobra, 108 for the 460 Ford King Cobra) of gear oil in there, check the dipstick, if it reads full, then screw it in and quickly remove the pump and replace the fill plug. Recheck the level, before running the drive. A number of Cobras have had their upper gears wiped out because people filled from the bottom plug, which can cause an air bubble to form, and then the drive will be underfilled.

 

[Master Mate Mike]

Re: OMC Cobra Stern Drive drain plug...uh-oh

Lou

Many thanks for the oil refilling tip!! I imagine once it warms up just a wee bit
here in norhtern Illinois, I'll take a crack at that damn plug.

I've received a lot of useful tips on here over the past week and I certainly appreciate everyone taking the time to write and share some insight.

Ok.....I'll post again when I find mhyself in deep **** and need more advice.

Thanks, Lou!!

Mike