How can I determine engine model number without placard?

[bl.burton]

Hello,

Quick intro:
Recently purchased a boat and am excited to begin working on it in the spring. Was told it was a 3.0. Looking to secure the model number from engine to determine exactly what Im working with. I can not locate a placard with the serial/model #. Supposedly located below the bell housing. I only found one stamp on the block which reads "322 85" and I do not believe this is significant.

I have searched without prevail and hoping to find some guidance. I have attempted to use the outdrive model # (983841) to determine the engine. This has only led me to believe I am looking at a OMC Cobra 1986 to 89 2.5 or 3.0.

Ultimately, I suspect it is a 1989 OMC Cobra 3.0L and would like confirmation. From there, I will secure a manual and parts guide to begin studying this winter.

Thanks in advance for any assistance, I hope to ask lots of questions come spring and am looking forward to taking boating on as a new hobby.

 

[bl.burton]

I have found a list of model #'s, posting here for my own reference and perhaps to assist others. If I am correct in my assumption, then I should be dealing with a 302AMRMED 3.0L 1989


https://maxrules.com/models/OMC_models_files/Stern/Cobra.html

 

[Scott Danforth]

With the 3.0, the main date to worry about is 1991.

There is 1990 and earlier motors and 1991 and later motors

 

[jerryjerry05]

That's a 3L
I'd worry about the carb being uncovered and the plug/cap missing on the cover.

The early Cobras/ the motor is the 4cyl. Iron Duke used in thousands and thousands of boats.
The 86 was the first year for the Cobra drive.
Myself no way would I buy a Cobra even if it was really cheap.
Get a Mercruiser or a late model Volvo.

 

[bl.burton]

Thanks! I plugged the oil cap with a rag, and put the air intake on the carb - both right after taking photos.

How can I confirm the year? I was hoping someone might have some knowledge of various parts I can inspect to start ruling out years. Or atleast which generations I can start ruling out.

As for OMC, yea, I agree with you from my research, not my experience. For now I'm going to focus on getting it running and cleaning up the boat. And once again thanks!

 

[Lou C]

On thing that can differentiate the model years is a grease fitting on the side of the pivot housing. This is to make it easier to grease the bellcrank inside and was added in '92, so if this is not present then its a '91 or older, the other marker is the presence of points ignition system under the distributor cap, this was changed in 1991. So if it has a points ignition it's 1990 or older. Electronic is '91 and up. Production of the original dog clutch Cobras ended in '93, for '94 it was re-engineered to cone clutch shifting and became the Volvo SX.

I've owned this one since 2002 and used it in salt water (moored) for 6 month seasons. It has held up extremely well, repairs on the drive system have been very few over time, in fact it has not been back to a mechanic since 2006, when it was last resealed. Compared to a Merc Alpha, the Cobra design is better in a few ways:

the good:
when in proper adjustment shifts better than an Alpha
better quality transom mount, not prone to hinge pin wear and steering play and leaks by the steering arm that plauges salt water used Alphas
impeller and d/s bellows much easier to change
shift cable bellows design is much better and if it tears will not sink the boat, in fact this design was continued with the Volvo SX and continued on to the later SXA

the bad:
most mechanics won't know how to adjust the shift cable design, I taught myself with a shop manual and a few special tools in a few hrs. And it shifts perfectly with 2 fingers.
some parts are getting hard to find.

this is an actual user review based on 17 years of salt water use.

 

[Scott Danforth]

from a base engine point of view

there is the 1990 and older 3.0 with a 2-piece RMS
there is the 1991 and newer 3.0 with a 1-piece RMS

outside the base engine, each marinizer added the fuel system, ignition system, mounts and accessories.

however most importantly, what does the riveted data tag on the side of the motor just above the starter boss state it is? (located under the solenoid plate)

 

[bruceb58]

Yes, there is not much difference between these year engines. The only difference that you really need to worry about is what distributor it has. Do you know if this has points or an electronic pointless ignition?

I have a 1990 service manual in PDF form. I can send you a link to the PDF. Just send me a PM.

 

[bl.burton]

Its got a distributor cap so I presume it has points. I will send PM

Scott, I was hoping to check it this weekend, but its snow covered so I didn't bother. I'll get back to you on that later this week as Its warming up over here.

 

[bruceb58]

Its got a distributor cap so I presume it has points. I will send PM

EDIT: you have points so a very early 90 or an 89 or older.

 

[bruceb58]

Just looked and both the 89 and 90 use points(Actually, the 90 version started to use the Voyager distributor within the model year). 91 they used the GM Voyager distributor.

I used this site as my reference:
https://www.crowleymarine.com/omc_p...-c2hHgg7-mtc2bii3EMYi02DhDHpMk6xoCxN0QAvD_BwE

 

[bruceb58]

Based on the fact you have 3 solenoids on the shift plate, you are 88 or older.

To be honest, it really doesn't matter much. These are all nearly the same in those years.

 

[Scott Danforth]

paint color changed a bit between 1974 and 1990, there were 3 different carburetors along the years, however the base motor did not change.

 

[jerryjerry05]

Usually the hull # will tell you the year.

 

[bl.burton]

Thanks everyone, this is great information. Cant wait for spring to come to start working on it. Will have more questions!