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Old Johnson 20

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caddy50

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I have an old Johnson Outboard (I think a 73 year model) It was my Father-In-Laws it hasen't been started in about 6 years or so, needless to say it probably needs a lot of work, I guess my first question would be how do I find out what year model it is? And I guess once I do that where can I get a service manual? I'd like to try to get it running without spending a small fortune. I just purchased a home on the water and I just thought about
buying a small Jon boat and using this 20hp on it, but again it's going to depend on what the cost would be to repair it.
any help would be greatly appreciated.
 
One of the best motors in that HP category.----Was basically the same from 57 to 77, so lots of new and used parts available.----Start with a compression test.----If that is good then clean carburetor ( usually no parts required there ) and see if it will run with fuel mixed at 50:1.--------Once you establish that runs you should install a new waterpump impeller , change lower gear oil.
 
caddy50 said:
I have an old Johnson Outboard. I guess my first question would be how do I find out what year model it is?
Click to expand...

Standing in back of the engine, facing the spark plugs.... Left is Port, Right is Starboard.

Now, on the port transom bracket (bkt that attaches eng to boat), there should be a small plate attached with the model and serial number of the engine. What is that "Model Number"?
 
During the 1970's the Johnson people had the year right in the model # -----------If it ends with say 73A then it is a 73 model.---If the cowling is in origninal condition, then a picture posted here will make for instant identification.
 
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racerone said:
One of the best motors in that HP category.----Was basically the same from 57 to 77, so lots of new and used parts available.----Start with a compression test.----If that is good then clean carburetor ( usually no parts required there ) and see if it will run with fuel mixed at 50:1.--------Once you establish that runs you should install a new waterpump impeller , change lower gear oil.
Click to expand...

dont mean to hijack, but really? :)
 
One of the best motors for someone trying to maintain it themselves.----Should be a " low cost of ownership " if you know how to work on them yourself.
 
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