Which OMC do I have?

[dursman]

Hi everybody, I'm new here and new to boating (I'm sure you'll be able to tell). I recently bought a boat and I wanted to get one of those Tech Manuals for it, but I have an '86 and it seems like there are two different OMC's for that year. My boat is a 1986 Chris Craft Cavalier. 18' Cuddy. I was told by the previous owner that the engine is a 205 hp 350 ci. Is there any way that I can find out if this makes the outdrive a Cobra, or non-cobra? As I said, for 1986 there are two different tech manuals and I just want to make sure I get the right one. Thanks. I've been reading and learning from this site for a while now and this is my first post.

 

[Boomyal]

Re: Which OMC do I have?

In 1986 OMC produced both the Stringer and the Cobra simultaneously. If you have the Stringer you will have an accordianed rubber boot between the protruding intermediate housing and and the transom. A Cobra will not have the boot but will have tilt cylinders.

 

[dursman]

Re: Which OMC do I have?

Thank you for the quick reply. I believe I have the Stringer because there is a big black rubber surround where the outdrive goes through the hull - as I said, I am new to boating and new to all of this boating terminology <br /><br />I am also looking for a new propeller on iboats and there are props for either the Model 800 (15 Tooth Spline) or Model 400 (13 Tooth Spline). I would venture a guess that I should be looking at the props for the Model 800 5.0 liter? Would I be able to find the Spline if I take the prop off and count the teeth where it gets connected?

 

[Mahoney]

Re: Which OMC do I have?

Yes, you should be able to just count the teeth on the spline and know which one to use. Wait for those on here to let you know how to find out the excact outdrive you have, model and year, that is going to be extremely useful in new posts or getting parts.

 

[dursman]

Re: Which OMC do I have?

Thanks Mahoney. From the info I've provided, can anybody tell me exactly what outdrive I have? Is there anything else you would need to know to be able to? Sorry again for the ignorance - I just don't want to buy parts that won't fit.

 

[recess]

Re: Which OMC do I have?

dursman, you should see a large half-moon shaped gear that is part of the tilt mechanism. This will be on the port(left) side when looking at the stern of the boat. This gear moves and lifts the sterndrive up for trailering. Also, on the top of the outdrive, the top cap should have a rubber bumper for protecting the drive from slamming into the intermediate housing when you lift it and there will be 5 bolts holding the top on. Check that and see. If you have an 8 cylinder, then you should have an 800. 400 was for the 4 cylinder models. Try going to this site http://www.sterndrive.info/ and follow the different models on the left of the page. Compare the drawings to what you have. The exploded view diagrams are really helpful.

 

[dursman]

Re: Which OMC do I have?

So looks like the outdrive is an 800 with 15 Tooth Spline. Now about the engine... its a GM V8 (I saw the "GM" and it has 8 plugs). Any way I can tell if its the 4.3, 5.0 or 5.7 liter? I thought the seller said its a 350 with a 2 barrel carb - but I'm not very sure. Any thoughts?

 

[Boomyal]

Re: Which OMC do I have?

Originally posted by dursman:<br /> Thanks Mahoney. From the info I've provided, can anybody tell me exactly what outdrive I have? Is there anything else you would need to know to be able to? Sorry again for the ignorance - I just don't want to buy parts that won't fit.

If you have a V8 you have an 800 model. That takes the 15 spline prop. You'd probably use a 15" x 17 or 19 pitch. Cupping the prop helps quite a bit as well.<br /><br />***DO NOT USE YOUR TILT MECHANISM FOR TRIM CONTOL. ONLY RUN IT IN THE FULL DOWN POSITION EXCEPT IN EMEGENCY FOR SHALLOW WATER. EVEN THEN DON'T RUN IT WITH MORE THAN ABOUT 20% UP POSITION AND ONLY FOR BRIEF PERIOD.****

 

[Boomyal]

Re: Which OMC do I have?

The 4.3 is a V6. The 5.0 and 5.7's are V8's. Both V8's are basically 350 chebby blocks. Maybe some Chevoholic can tell you the external visual differences between them.

 

[Boatin Bob]

Re: Which OMC do I have?

Should be a mod/sn plate on one of the rocker covers, if you can provide the model # then we can out for sure the year and engine size.

 

[TilliamWe]

Re: Which OMC do I have?

and if you can't find serial numbers, on the rear of the engine block, where the bellhousing bolts to it, there will be number cast into the flange. It will either say 5.0G or 5.7G. Guess what those mean (the G is for "gasoline") This number will be on the top of the flange, on the left side of the block, kinda directly behind the left head.

 

[dursman]

Re: Which OMC do I have?

Just got back from checking for the model numbers... and couldn't find any. Didn't look like there were any on the rocker covers and I don't really know what a bellhousing is, but checked everywhere on the back of the engine that I could see and couldn't find anything. I just ordered the tech manual so maybe that will have some pictures showing where I should look. All I could find was a model # and serial # on the outdrive. Thanks again for all of the help.