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    1973 merc 20 hp ignition issue

    I picked up a near new 1973 merc 200 and after putting it in the water found it was running on one cylinder. Swapped the coils and spark followed the coils, so I figured it must be the one coil and ruled out the switchbox. So bought a new coil and installed and fired right up as it should when...
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    installing propshaft needle bearing in gear housing

    My new project is a 1960 merc 700 Dr and need to install a new propshaft needle bearing into the gear housing. Got the old one out with alot of patience and a dremel, so now I'm wondering what is the proper way to install the new one. Anybody have any good tips to keep things straight and...
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    Adding temp sending/gauge to mark 78

    I sure would like to install a temperature gauge on my old mark 78. Is it possible to retro one that measures the water temp rather than the surface sensor on the exaust plate?
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    1958 Mark 78 backfiring when starting

    Hello,<br />My Mark 78 ran just fine last year-no problems. <br />Put the boat in a few weeks ago and will not start- try's a few times and then starts backfiring through the exaust. Checked plug wires, replaced plugs,pulled dist cap and had about 1 teaspoon of water in it. I puzzled over how...
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    De-Carbing old Mark 78

    I have a 1959 mark 78A which is running ok-starts good and runs out. Maybe a little rough on idle, although I really do not know how well they are supposed to idle in tip top shape. I have read alot of posts concerning decarbing. We have had this motor in the family since new and I'm pretty...
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    mark 78 lower gear case seals

    I have my water pump housing off and now I'm looking at the cast pressed in insert that holds the stainless impeller cup. What is the best method to remove that insert so I can get at my lower seal? I know there is a special tool, but can it be done without it and not destroying that piece. Any...
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    Lower gear case on Mark 78

    Hello<br />Does anybody know if I can use a Mark 75 gear case on a Mark 78. Everything appears to be the same that I can see. I have the opportunity to pick one up pretty cheap, which I thought would be a spare for my 78 if mine ever went sideways.<br />Thanks
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    Right Tach for motor?

    Hello<br />I have a 1958 Mark 78 Merc that I would like to install a tach on. I purchased a 'vintage' Airguide #690 tach which was supposed to work on a 6 cyl outboard. The back of the tach has 4 jumper positions. There is a tag on the back with these instructions:<br />2 cyl magneto connect...
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    cooling on mark 78

    I have a 1958 Mark 78 Merc we have had in the family since new. It was not running when I started this project I have got it running now, but have some concerns with lack of water coming out the exaust, since this is the only place I can find where the water would exit. There is no small hole...
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