1986 OMC Cobra OD

jessejameslnw · Apr 6, 2013

I bought an '86 18' VIP with 5.7/OMC Cobra last year. It is the first I/O I've owned and certainly the first OMC. While I have the owner/operators manual, while winterizing, I removed a plug from the port side of the drive that apparently should have had a decal over it. (decal must me missing, darn it wrong plug!) When I tried to reinstall the plug, I noticed there was no longer anything there to hold it in place, like a nut... So my question is, will removing the lower unit enable me to find the nut? Is there a nut? I've owned and or just worked on Mercs and Evins, so I figured when I pulled the lower to replace the water pump I may be able to find it laying there for me to re-install. However, today, I find the water pump on the Cobra has it's very own little handy cover. Nice, lol. I planned to change the oil in the OD, but if I have to pull the lower to find this nut, is there anything else I should have handy like gaskets etc? Thanks!!

jerryjerry05 · Apr 6, 2013

Re: 1986 OMC Cobra OD

Yup you'll find the other half of the screw.
No need to pull the lower.
Just loosen the drive and back it out and reach in and find the nut.
Make sure when changing the oil you fill from the right place????
If you fill from the bottom you'll destroy the drive.
It's filled from the side screw,just above the cavitation plate.

jessejameslnw · Apr 6, 2013

Re: 1986 OMC Cobra OD

jerryjerry05 said:
Yup you'll find the other half of the screw.
No need to pull the lower.
Just loosen the drive and back it out and reach in and find the nut.
Make sure when changing the oil you fill from the right place????
If you fill from the bottom you'll destroy the drive.
It's filled from the side screw,just above the cavitation plate.

Wow! The entire drive? Possibly a stupid question, but it looks like a lot of reaching to reinstall the nut.. Is there enough room to do so without pulling the drive completely? Also, I'm assuming there may be a gasket? Knowing my luck it would tear... and I'd be without paddles. Anything else I need to do while I'm in there? It won't fit in my shop with the doors closed, and I travel for a living so just want to be prepared before I dive in. Thanks again.

bonzoscott · Apr 6, 2013

Re: 1986 OMC Cobra OD

I'm no authority but I have read much on the OMC stern drive. They are obsolete and out of business, so I figure I better get one step ahead. I have read that the nut you're speaking of must have the drive off to retrieve. While you have the drive off, there is a number of things you should check and or replace. i.e. Gimbal bearing, coupler, bellows, U-joints, alignment, etc. Suggest you search and do much reading as I did. Plus OEM service manual. Best of luck.

Don S · Apr 6, 2013

Re: 1986 OMC Cobra OD

I have always had to pull the drive, turn it upside down and forward to get that nut plate to where I could get a screwdriver on it to line it up with the hole.

The drive should be being pulled yearly for simple maintenance like greasing the coupler splines, checking the alignment, greasing the gimbal bearing and cleaning up the old grease etc.
If necessary, pull the drive off, close the doors and leave the boat outside. Just cover the opening with a plastic bag to keep the rain out.
Yes there is a couple gaskets and orings.

wcasey5 · Apr 6, 2013

Re: 1986 OMC Cobra OD

Not a big deal to pull the drive. 6 nuts. You will need a gasket to re-install, and preferably an alignment tool. It will give you a chance to inspect and/or change the bellows, and grease the u joints at the same time.

Some engineer at OMC must have had a sick sense of humor putting that screw where it is.

jessejameslnw · Apr 6, 2013

Re: 1986 OMC Cobra OD

The random questions are cracking me up! lol. I agree that someone laughs every time this happens... Thanks everyone for the input, it'll be next weekend before I can start the project, hopefully I can get parts ordered and delivered by then. I do know that I am third owner and the boat has been well taken care of.. everything is clean as can be including gear oil etc. I'd like to keep it that way. Thanks!

jessejameslnw · Apr 7, 2013

Re: 1986 OMC Cobra OD

I'm browsing ebay for for the alignment tool, gaskets, and a manual as I've seen so many of you guys recommending them. But I'm having trouble finding an older OMC drive manual, they seem to all be mid '90's. I believe this one is actually an '87. Is there a newer manual that will work?

HT32BSX115 · Apr 7, 2013

Re: 1986 OMC Cobra OD

jessejameslnw said:
I'm browsing ebay for for the alignment tool, gaskets, and a manual as I've seen so many of you guys recommending them. But I'm having trouble finding an older OMC drive manual, they seem to all be mid '90's. I believe this one is actually an '87. Is there a newer manual that will work?

Howdy,

I had one of those! (A 1987 Cobra and a 1987 Cobra manual!)

They're pretty scarce. You have a very obsolete engine and drive. The manuals are also pretty obsolete and you're sort of at the mercy of whomever has one and wants to part with it.

Here's one I found on ebay just now. 1987 OMC Cobra Stern Drive 2 3 3 4 3 5 5 7 7 5 Service Repair Shop Manual | eBay

If I were you, I would get it before someone else does.

I paid $100 for the one I had and it was a reprint! I gave it to the guy I sold my 87 King Cobra drive to.

Sorry about that,

Regards,

Rick

jessejameslnw · Apr 7, 2013

Re: 1986 OMC Cobra OD

OUCH! lol. Thanks! I didn't get any results, but I rarely do with ebay searches. It is in fact an '87, had to locate the title to be sure. I'll take your word for it and hit that little button, hopefully, I'll be able to get away without the alignment tool this time. I plan on keeping the boat, it's super nice for it's age so the manual should come in pretty handy.
Thanks for the link Rick!

HT32BSX115 · Apr 7, 2013

Re: 1986 OMC Cobra OD

Yeah. I REALLY didn't like paying $100 for the reprint and to add insult to injury, right after I bought the thing, a couple of weeks later someone posted a really nice condition 1987 OMC Factory manual on ebay for something like $40!!! :mad-new:

And to make matters worse NO ONE BID ON IT!!!!!!\

I hate when that happens! It's always my luck. If you're not in a huge hurry, wait a little while and/or offer the dude less. Those things show up on there from time to time. but they ARE getting rarer and rarer......

I would definitely want the right one since they did change some things from year to year......

btw, join the club on removing the "Never Remove Screw"!! ......... you need to pull the drive anyway if it hasn't been done since you got it.....ABOVE ALL, when you R&R the drive oil, follow the OMC service instructions on the procedure exactly. doing it wrong will destroy the drive!

Good luck,

Rick

jessejameslnw · Apr 7, 2013

Re: 1986 OMC Cobra OD

Sounds like stuff that happens to me. lol! I went ahead and bought it, someone will probably try to give me one next week, and I'll take it! I also ordered the alignment tool and gaskets, and found a listing for the OMC Hi Vis oil that stated he had cases, but would only let me get one 32 oz bottle at a time without calling... So what's the next best thing to use? I should probably start using something that will be readily available in the future... The owner's manual has the re fill instructions for the drive, and I have bookmarked links I've found on here about it.

HT32BSX115 · Apr 7, 2013

Re: 1986 OMC Cobra OD

jessejameslnw said:
found a listing for the OMC Hi Vis oil that stated he had cases, but would only let me get one 32 oz bottle at a time without calling... So what's the next best thing to use? I should probably start using something that will be readily available in the future... The owner's manual has the re fill instructions for the drive, and I have bookmarked links I've found on here about it.

Most of us like Mercury HP synthetic. Others also like Mobil 1 synthetic gear lube or even (Sc)amsoil Marine gear lubricant and many others.

Nothing wrong with the OMC Hi Visc....but I wouldn't go out of my to obtain it.....

I prefer something I can buy locally. (Walmart usually has the Mercury and Mobil 1, and a local NAPA has the Amsoil.....I have to drive about 30 miles if I want to use Mercury because my local Walmart doesn't have Merc HP)

Ask here about what to use and you'll get a "zillion" answers that sound like : "I use xxx oil and have never had a problem" You can believe them. Everything has been tried (except maybe engine oil) and no one ever reported back that it was a "problem"!!

Just make sure that it's Gear lubricant. (There's NO ASTM standard for "Marine" gear lubricant)

For online manuals, the following one is not bad. It's just really slow loading sometimes... Boatinfo - The library, containing manuals, brochures and other technical documents from the last hundred years!

jerryjerry05 · Apr 8, 2013

Re: 1986 OMC Cobra OD

When they made the drive.The hole there was a casting plug.
OMC in their infinate wisdom,thought we'll just cover it with a sticker and not tell anyone about it.
The early parts diagrams didn't even show the pieces.
Then the sticker started falling off and people with big screwdrivers started tinkering and you know the rest.
I made up a coat hanger plug holder thingy.That I could snake the plug back in without removing the drive.

HT32BSX115 · Apr 8, 2013

Re: 1986 OMC Cobra OD

jerryjerry05 said:
When they made the drive.The hole there was a casting plug.
OMC in their infinate wisdom,thought we'll just cover it with a sticker and not tell anyone about it.
The early parts diagrams didn't even show the pieces.
Then the sticker started falling off and people with big screwdrivers started tinkering and you know the rest.
I made up a coat hanger plug holder thingy.That I could snake the plug back in without removing the drive.

That's a great way to do it unless you really need to remove the drive for other reasons. (like the OP does)

jessejameslnw · Apr 9, 2013

Re: 1986 OMC Cobra OD

Ok. Thanks all for the help and input once again! I found some Lucas 80/90 gear oil at my local Atwoods, says it's excellent for outboard final drives. I've used a lot of their product and know plenty mechs that have for years. My only concern is the thickness.

I was supposed to go up North (Western Nebraska & Eastern Wyoming) for work this week, but they are expecting 12"+ of snow, so luckily my boss pushed it back a week. It's not fun pouring concrete in the snow! lol.

So anyway, I am awaiting the manual, alignment tool, and gaskets in the mail. They have all been shipped, so hopefully I'll get them in time to work on the boat before next week. The only other things I have to find are the new seals for dipstick, drain, and fill plugs. Maybe I will be able to find them at Ace or Napa here in town. I'll certainly come back and let you all know how it went.... IF I don't have to come back with more questions first!

jessejameslnw · Apr 11, 2013

Re: 1986 OMC Cobra OD

So all the parts are in and I thought I'd change the water pump while waiting on the oil to drain... There are pieces of the impeller missing (not to my surprise, doesn't look like it has been changed in a while if at all for the paint on the housing, gask, etc...) So my question is should I look for the pieces? It never overheated last summer.

HT32BSX115 · Apr 11, 2013

Re: 1986 OMC Cobra OD

jessejameslnw said:
So my question is should I look for the pieces? It never overheated last summer.

You should ensure that the raw water path from the pump to the t-stat housing is unobstructed by debris or kinked hoses etc....

coolbri70 · Apr 11, 2013

Re: 1986 OMC Cobra OD

had no idea the manual was valuable, i put it in a box in the garage thinking it was useless, cant remember which box, i did have to go search, havnt found it yet, but i know its there:facepalm: think i will be setting it aside next time i find it.

HT32BSX115 · Apr 11, 2013

Re: 1986 OMC Cobra OD

coolbri70 said:
had no idea the manual was valuable, i put it in a box in the garage thinking it was useless, cant remember which box, i did have to go search, havnt found it yet, but i know its there:facepalm: think i will be setting it aside next time i find it.

The "value" of something always depends on how badly someone else wants it!

1986 OMC Cobra OD

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