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    1980 3.0L strange overheat issue

    One thing I need to ask those in the know. Is that annoying low oil pressure buzzer somehow interlocked to cut out the ignition if low oil pressure is detected? I’m asking because some of the diesel GPU’s we have at work have a time delay on the oil pressure. It’ll run for a few seconds then...
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    1980 3.0L strange overheat issue

    I’ll be at it again this weekend and figured I best leave the fuel line disconnected and crank the engine to pump out a cup of fuel into a clear container and check for water. I ordered a water separator kit and will also get that installed this weekend. I also have a new filter to replace the...
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    1980 3.0L strange overheat issue

    I disassembled the carb and it wasn’t pretty. The first photo is the fuel inlet filter, the second is the fuel inlet and finally the fuel I sucked out with a large syringe. The murky stuff at the bottom is dirt and water I ran the carburetor through 2 short cycles in the ultrasonic cleaner...
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    1980 3.0L strange overheat issue

    I already have the carb kit (Napa) the ultrasonic cleaner I’m using at work will be the one used for turbine fuel system components. I’ll run it through a short cycle then inspect it. It would be nice if the problem was something simple like a low float level but if that was the case, the higher...
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    1980 3.0L strange overheat issue

    So far I really haven’t had a lot of time to work on it. I’m leaning toward fuel delivery as I’m not sure how old the fuel filter on the pump is. I picked up a new filter which I’m hoping to replace today. I also picked up a rebuild kit and if the filter and adjustments don’t help, I’ll take the...
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    1980 3.0L strange overheat issue

    I found an NOS gear on eBay and it’s all back together. The machine shop only charged $100 to replace the valve and resurface the head. I took it out on the lake and no overheating!! The new problem is run ability. It fires up quickly then pretty much immediately dies. It takes several attempts...
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    1980 3.0L strange overheat issue

    I decided while waiting for the cylinder head to check the impeller. It is actually intact and not hardened. Unfortunately, the gear on the shaft behind the impeller has a couple broken teeth and the gear it drives needs new bearings as they are hard/rough to turn. The price of these gears (even...
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    1980 3.0L strange overheat issue

    I dropped the head off at the machine shop. They’ll check the valves, replace the cracked valve and resurface the head.
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    1980 3.0L strange overheat issue

    Ok. I have the riser and coupling hose off. I’ll look inside and see if it is there. I went through my manual a couple times and there was no mention of it. I looked for the part online and only found one listed for a Cobra not a stringer. I’ll verify visually. I check inside the exhaust...
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    1980 3.0L strange overheat issue

    Where are they located? Would it be where the exhaust adapter meets up with the outdrive?
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    1980 3.0L strange overheat issue

    Ran into another problem. I pulled the cylinder head to clean out the cooling passages as well as check the block passages. I did find the small passages on the head where cooling water comes from the block were partially to fully blocked. They have been cleared and flushed out. The small...
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    1980 3.0L strange overheat issue

    I’ve found a few places that have the 3.0L replacement which is what I have. I’m am however going to run it with this manifold for now to make sure this is actually the problem. I’m still going to pull the head and water pump and check all the cooling passages to be sure they are fine. This...
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    1980 3.0L strange overheat issue

    Finally back at this issue. I have the manifold off and took off the front cap. Quite a bit of rust buildup. I flipped it end for end and took off the cap on the riser end. I found this. That’s a 1 1/2lb ball pien for comparison. There’s still more to scrape out. Needless to say, this is most...
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    1980 3.0L strange overheat issue

    Thermostat installed. Same results. Anything over 3/4 throttle results in overheating. I have an engine gasket set but have decided that I’ll just run the boat below the overheat point until I’m ready to put it away for the season. I figure it’s better to be able to run it lightly than to risk...
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    1980 3.0L strange overheat issue

    That I believe is the issue. I can run all day at about 1/2 throttle and temp stays around 125-135° Once up to 3/4 and beyond the temperature climbs fast. Thank you for this.
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    1980 3.0L strange overheat issue

    I assume you are referring to the swivel that permits steering. This is my first ever stern drive so it’s a bit of a learning curve. One question. While searching around the net, I’ve heard talk of exhaust flappers. Would this drive setup incorporate these?
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    1980 3.0L strange overheat issue

    I ju I just find it strange that overheating occurs with the thermostat removed. The engine runs strong and there’s no associated head gasket issues ie; rough idle, hard starting due to water intrusion, water in oil etc. That said, a complete gasket set is on the way so I’ll probably just take...
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    1980 3.0L strange overheat issue

    I came across an article online regarding manifolds. It stated if an engine runs at normal temperature under light to moderate load but overheats at high speed/load, the most likely culprit is blockage of the manifold. I have also downloaded an older OMC factory service manual which backs this...
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    1980 3.0L strange overheat issue

    Finally put my 1980 Starcraft in the water last weekend. Loaded the family and dogs and went up the lake to a nice beach. Just as we got there the engine overheated. We pulled up on shore and waited until things cooled a bit. I pulled the feed hose from the impeller to thermostat housing and...
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    Omc 5.0 Replaced starter, and solenoid, no power

    Yellow/red to the “S” terminal on the starter solenoid.
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