OMC upper unit.

[ben2017]

here is the image the guy has, there is a cobra stamp on it.



"This is the upper half of the sterndrive/outdrive and is the most common part that goes out when the lower unit gear lube is low. Came off a late 1980s boat with a 4.3 liter OMC motor and will work on 5.0 and 5.7 liter OMC motors. Comes complete with drive shaft, U joints, etc."

so this is the post I read where it is for sale, my question is will this fit my 4.3 OMC Cobra? My boat is a 1992 Four Winns. (sorry I dont have the sr# right now). How much changed on them from the late 80s to early 90s?

 

[Don S]

Re: OMC upper unit.

Two completely different kind of outdrives. Nothing is interchangable.
The 80's is an old stringer type outdrive, the 92 is a Cobra outdrive.

 

[HT32BSX115]

Re: OMC upper unit.

"This is the upper half of the sterndrive/outdrive and is the most common part that goes out when the lower unit gear lube is low. Came off a late 1980s boat with a 4.3 liter OMC motor and will work on 5.0 and 5.7 liter OMC motors. Comes complete with drive shaft, U joints, etc."

so this is the post I read where it is for sale, my question is will this fit my 4.3 OMC Cobra? My boat is a 1992 Four Winns. (sorry I dont have the sr# right now). How much changed on them from the late 80s to early 90s?

It possibly might work.....

Came off a late 1980s boat with a 4.3 liter OMC

If it came off a "late 1980's" OMC engine/drive, and that means 1987-1989,

Then it is probably a "Dog-Clutch" Cobra.


If yours is a 1992 "Dog-Clutch" Cobra, (which in 1992 was bolted to the 4.3L engine) then it is very possibly the same. ........ and may work.


If "Late 1980's" means (early) 1986 (and/or earlier), then it's a Stringer......and then, no, it's a completely different drive.



Cheers,


Rick

 

[Don S]

Re: OMC upper unit.

If it came off a "late 1980's"

Ooooops. Missed the word LATE. Only read 1980 :redface:

 

[ben2017]

Re: OMC upper unit.

 

[HT32BSX115]

Re: OMC upper unit.

Is that the one you're wanting to buy?

If so, it should work if it's the correct ratio.

The only way you'll be able to determine if the upper ratio is the right one will be to pop top cover off and count teeth.

I don't have an OMC service manual any more. The ratio is in the manuals. I also don't know if I would necessarily believe the seller..........that it's the "correct" ratio until you verify it.

I just did a little searching around and found the following. At eBasicpower

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Gear Set, Upper, OMC Cobra 86-93, 21:19, 4.3L V6

The 21:19 means 21 teeth and 19 teeth! (which is also the upper ratio too)


If it's the above ratio, then it's probably the "right" one to hang on the back of a 4.3L V-6.


Cheers,


Rick



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[ben2017]

Re: OMC upper unit.

Great thanks for the responses, Ill check on the ratio.

 

[ben2017]

Re: OMC upper unit.

UPDATE: well I bought the unit and it fit perfect, boat ran great this past weekend. UNIT+Shipping+labor to install=$850. I think I got really lucky.

 

[HT32BSX115]

Re: OMC upper unit.

I love it when a plan comes together.....


Be aware of the fact that you bolted a used/unknown "upper" onto a used "lower".


That means that if there's any issues in either, you could have a drive that might still self destruct. At the end of this season, you should drain the drive oil and inspect for metal etc and replace (fill according to the correct OMC Cobra procedures!!!)


If self destruction happens in the future..... you'll be rebuilding/replacing as required. Keep in the back pocket the future option of just switching the whole mess out for the SEI.


Meanwhile, Have a great summer with that thing!!



Cheers,


Rick