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1980 mercury 50hp 4cyl

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AaronMerc

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Hello, I’ve been trying to get this motor running all summer, it will run just fine on throttle only, revs up like crazy, but not in gear it has spark in all cylinders, fresh fuel, new plugs, new stator, new trigger. I believe it’s something to do with the lower end, any ideas would be much appreciated. I will leave a picture below of the last time I took it out it was spitting water from a place I hadn’t seen before, and it was very milky around it, it don’t look good to me but Im just not sure what would cause that
 

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Compression is around 120 in all cylinders, I just put a new stator on and the flywheel key was still on, I suppose it could’ve sheared off since, I’ve also managed to get the power head off to look at where the leak was coming from and it’s the steering mount system that connects to the mid section not sure what it’s called, it seems very loose. I can’t manage to get a wrench on to tighten them yet. It will run good on muffs or in a bucket, but in the water it will only go around 5mph. I have not broke into the carbs yet but maybe I should just to see. Thanks for your reply @racerone
 
Got everything back together and the motor is still running the same (maybe a bit better) I had a sneezing problem with it before, I have since got to go away with adjusting the idle mixture screw rebuilt the top carb fuel pump, thought it could have been that to no change, but if I unplug the 2 spark plug wires it will run the exact same I have tested them for spark and they jump a gap just fine, they are wet when I check them after running. This is my first time trying to diagnose an outboard. PITA
I’m stumped at this point, would it be a good idea to check the power pack and if so does it require an ohm meter?
Thanks for reading my bullshit
-Aaron
 
I will be getting a volt meter Tomorrow to test the electrical, also when I had the motor apart the exhaust was about plugged full of carbon but after cleaning it made no difference maybe slightly
 
Also the motor will only idle nice with the idle screws about 1/4 turn out from lightly seated, maybe time to replace those? Or is it something else? both idle screws make the motor stumble when adjusting, also you can choke the motor out by covering the air intake (both carbs) which makes me think it’s running on all 4. It will run okay with the bottom plugs hooked up and then if I switch to the top plugs it won’t fire at all but will die if I choke out the top carb, only problem is out in the water it doesn’t have the power it should
 
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