Stringer - Questions, Questions and More Questions

tazman85305

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Sorry, it's http://boatinfo.no/lib/library.html#

And they don't have any Stringer manuals. :blue:

Ken Cook at Outboard Books has OEM manuals here - http://www.outboardbooks.com/index.cfm/model/1/308/ A hard copy of a factory manual is the best one to have anyway.


I am new to owning an OMC I/O. First off, is OMC MerCruiser? What does the O stand for? I am also looking for a manual on the outdrive of my boat, as I am trying to find the best way to run the motor while out of the water. I saw on an old post that there is an adapter for the pivot plate that has a hose attachment. Does this sound right to anyone? I am looking at a manual on boatininfo.no and I am not sure which outdrive I have. Can anyone help with that as well? My outdrive looks very similar to the one in the pic. outdrive.jpg
 

superbenk

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I am new to owning an OMC I/O. First off, is OMC MerCruiser? What does the O stand for? I am also looking for a manual on the outdrive of my boat, as I am trying to find the best way to run the motor while out of the water. I saw on an old post that there is an adapter for the pivot plate that has a hose attachment. Does this sound right to anyone? I am looking at a manual on boatininfo.no and I am not sure which outdrive I have. Can anyone help with that as well? My outdrive looks very similar to the one in the pic.


OMC is not Mercruiser. OMC stands for Outboard Marine Corp. & they went out of business about 15 yrs ago. Completely different company than Mercury.

There is an adapter you can buy that replaces the trunion cap on the starboard side that has a hose connector on it for running the drive in the driveway. You might need to check eBay or someplace to find it. I don't have the part number or link handy.

The outdrive in the pic is an electric Stringer (pre 1978). If you have a cone over the center of the prop & no through-prop exhaust (like in the pic above) you have an electric Stringer. If you have through-prop exhaust you have one of the variations of mechanical shift Stringers. 1978-1980 were hydromechanical (used hydraulics to help do the shifting inside the drive). 1980-1986 were full-mechanical shift & used an ignition retardation to assist in the shifting process (caused the engine to stumble slightly to allow the clutch dog to engage without pressure from the engine).
 

GA_Boater

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Welcome aboard.

Moved your post to a new thread because you aren't just asking about a source for a manual. Look at the Help Tip on top of the page.

Outboard Marine Corporation

If your boat looks like the one in the photo, you have an OMC Stringer drive. The large rubber diaphragm is the clue. Boatinfo has no Stringer manuals as I said in the quote.
 

southkogs

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Welcome aboard Tazman - Ben's gotcha' right: it's an electric shift Stringer.

Hose adapter would typically be on the pivot cap opposite of the one shown by the red arrow in your photo. Optionally, you could install a flush kit (T-connector from the auto parts stores) on your water line going into your thermostat housing. It'll provide water nearly as well.

On the inside of your engine bay - look for a tag: on mine it's on the rear motor mount on the starboard side. That tag has the model number of the drive : engine and all. You can use that model number to help hunt parts and so on. It's mostly defined by year and HP, but the number doesn't really help you figure that out - for example my Stringer is a JUFM10S.

Buncha' good information in the Stringer link in my signature.

Do a couple more posts and then you can upload some photos of your set which can help us answer questions for you.
 

tazman85305

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I was asking about a manual. I just asked a few more questions since the people on that thread seemed to know whay they were talking about and I am new to the boat scene....
 

tazman85305

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OMC is not Mercruiser. OMC stands for Outboard Marine Corp. & they went out of business about 15 yrs ago. Completely different company than Mercury.

There is an adapter you can buy that replaces the trunion cap on the starboard side that has a hose connector on it for running the drive in the driveway. You might need to check eBay or someplace to find it. I don't have the part number or link handy.

The outdrive in the pic is an electric Stringer (pre 1978). If you have a cone over the center of the prop & no through-prop exhaust (like in the pic above) you have an electric Stringer. If you have through-prop exhaust you have one of the variations of mechanical shift Stringers. 1978-1980 were hydromechanical (used hydraulics to help do the shifting inside the drive). 1980-1986 were full-mechanical shift & used an ignition retardation to assist in the shifting process (caused the engine to stumble slightly to allow the clutch dog to engage without pressure from the engine).


The electric part would be in the trim, yes?
It sounds like I do have the electric Stringer. Is Stringer a name brand or a model type?
 

tazman85305

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For clarification, I own a 1975 AMC Slickcraft with an OMC 235 inboard and what is begining to appear as a Stringer drive
 

tazman85305

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Welcome aboard.

Moved your post to a new thread because you aren't just asking about a source for a manual. Look at the Help Tip on top of the page.

Outboard Marine Corporation

If your boat looks like the one in the photo, you have an OMC Stringer drive. The large rubber diaphragm is the clue. Boatinfo has no Stringer manuals as I said in the quote.
I have the large diaphragm in the back.
Stringer drive good or bad? I am a mechanic so doing the work isn't a problem. Need to know life expectancy and tips to keep it running after 40 years
 

Scott Danforth

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Neither good or bad. Just obsolete like the dodo bird.
 

southkogs

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The electric part would be in the trim, yes?
Nope. Electric motors do run the tilt (motor at the back by the quadrant gear that lifts the drive up and down) and trim (if you have it will be at the front of the engine). But the "electric" part that gives it it's name is the shift. Most drives are shifted by a mechanical process now, but the old Stringers used electricity to power a coil/magnet and that's what put the lower unit into gear.

Is Stringer a name brand or a model type?
OMC is the brand. Electric Shift Stringer is the type of drive. See below for the model:

For clarification, I own a 1975 AMC Slickcraft with an OMC 235 inboard and what is begining to appear as a Stringer drive
Not just appearing :) It's an Electric Shift Stringer. Post number 4, I gave you a tip on how to find the model number. The engine on a '75 235HP should be a Ford 351 and the model number should be something like 990240AST. The Stringer Info link in my signature will have some information on the drive, but you will want a good manual for it.

Where do I find a manual on the Stringer drive?
The link in post 1 should have the OEM shop manuals I believe. You can also find them on eBay.

I have the large diaphragm in the back.
Stringer drive good or bad? I am a mechanic so doing the work isn't a problem. Need to know life expectancy and tips to keep it running after 40 years.
That diaphragm is the transom seal or transom boot. Make sure it's in good shape. They can last a very long time, but when they let go that's a big hole for water to come in.

The Stringer is not a bad drive at all. It's old like Scott said, and some parts are getting hard to find. I've kept mine going for six years or so for not too much money, and the inline 6 in mine is original to the boat (drive is collected parts). It'll want attention in the garage, and you do have to keep an eye on maintenance. But there's no reason it shouldn't run for a very long time.
 

tazman85305

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Welcome aboard Tazman - Ben's gotcha' right: it's an electric shift Stringer.

Hose adapter would typically be on the pivot cap opposite of the one shown by the red arrow in your photo. Optionally, you could install a flush kit (T-connector from the auto parts stores) on your water line going into your thermostat housing. It'll provide water nearly as well.


I have been looking, unsuccesfully, for an explantion on how the cooling system operates. I have a few pics of the cooling system and was hoping you could explain.

eng cooling 1.jpg eng cooling 2.jpg eng cooling 3.jpg
 

tazman85305

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I was thinking that the hose that runs from the thermostat, down the valve cover, to the section of the outdrive that attaches to the motor, was the intake for the cooling system. But I can't figure out how water gets from the lake, into the motor. I really want to run this motor, but I don't want to burn it up
 

southkogs

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From the lake, your drive has a pickup on the underside near the prop. Here's mine:


The Stringer is completely submerged, so when you put the boat in the water that drive is pretty quickly flooded with water. There's an impeller in the drive that circulates water up toward the engine, and then there is a circulation pump in the engine that moves it to cool. Upper left photo, you have the red line on the intake hose. The hose above that one, and the hose you have on the red line on in the upper right photo are outlet hoses running to the exhaust manifolds. When the T-stat is closed water goes out those lines, and down to the drive to exit back whence it came :)

Bottom hose in the upper left shot is the outlet hose to the circulation pump. When the stat is open, water goes into the engine to circulate and cool ... ultimately making it back down the exhaust route.

I think this diagram is your engine (not positive though):
235_COOLING.png
 

tazman85305

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So there is a water pump inside the Stringer? That was what I was wondering. I was taking off that hose and submerging it in a bucket of water thinking it would suck the water in. That is the same line that you suggested I install a flush tee in and just hook the hose to it?

Looking at your drawing, the water pump only works when the prop is turning, is that correct? How does the motor stay cool at idle?

To ensure that the pump is working, if I install the flush tee, I should get water pumping out the tee if I pull the cap off? I really wish there was a way to ensure there was water flowing through the system....
 

Bondo

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So there is a water pump inside the Stringer? That was what I was wondering. I was taking off that hose and submerging it in a bucket of water thinking it would suck the water in. That is the same line that you suggested I install a flush tee in and just hook the hose to it?

Looking at your drawing, the water pump only works when the prop is turning, is that correct? How does the motor stay cool at idle?

To ensure that the pump is working, if I install the flush tee, I should get water pumping out the tee if I pull the cap off? I really wish there was a way to ensure there was water flowing through the system....

Ayuh,.... Welcome Aboard,.... The raw water comes From the drive, out of that hose,...

Nope, Not correct, everything but the prop shaft turns with the motor, the drive shifts F, N, R, Below the water pump,....

Only if the boat is in the water, the drive fully submerged,.....
 

southkogs

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So there is a water pump inside the Stringer?
There is a water pump - typically called the impeller - in the bottom of the upper gear case of the drive (what you're calling the Stringer, I think). There is also a circulation pump up in the engine itself.

I was taking off that hose and submerging it in a bucket of water thinking it would suck the water in.
Nope ... drive will move water, but it won't suck it. The system is designed to be completely submerged in water, and that will automatically fill it for the impeller to move the water around. On a trailer, you kinda' have to "force feed" it.

That is the same line that you suggested I install a flush tee in and just hook the hose to it?
That line would be the bottom hose that you marked in red in the upper right photo.

Looking at your drawing, the water pump only works when the prop is turning, is that correct? How does the motor stay cool at idle?
Nope - Like Bondo said, the impeller is spinning when the upper gear case is spinning ... which is anytime the engine is on.

To ensure that the pump is working, if I install the flush tee, I should get water pumping out the tee if I pull the cap off? I really wish there was a way to ensure there was water flowing through the system....
If you have the boat in the water ... and open the flush T, then you should have water flowing out (I'd have to look up how much). If you have the boat on the trailer, and the hose adapter on the pivot cap, you should have water flowing out of where that flush T would be. If you stick the drive into a bucket of water, you won't get anything most likely.
 

tazman85305

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I installed the flush kit adapter tonight and ran the engine. Idles at about 155 degrees on the trailer. VERY VERY HAPPY!!! Thank you everyone for all your help. I will be getting the tires on the trailer replaced tomorrow and then hope to run around the marina on Sunday. Engine runs like a champ. According to the tach, 5K RPM's is about max, then the engine gets a little upset. I think 3.5K should get me across the lake pretty good..... Oil pressure, voltage, temp all look good. Very excited to get this bad boy into the water!
 

southkogs

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WOT operating range should be between 3,800 - 4,300 RPM. Don't overwind it ;)
 
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