1974 StarCraft - 50HP Johnson Motor

bprz09

Cadet
Joined
May 28, 2012
Messages
18
I am new here and I am also known to the world of boat motors. I know the basic concepts from the work I've done from rebuilding Atv motors and doing motor swaps in cars, but I know there is a lot more going on with boat motors so I would appreciate any help and advice I could get. Last summer I picked up my first boat a 1974 Starcraft with a 50HP Johnson Motor, the owner said he had let it sit for 7 years and said that the boat was winterized ( I am not too sure how true that is). In any case he said he it hadn?t tried to start the motor, so I picked it relatively cheap. I got the motor to start and gutted the floor out. I am in the process of putting the carpet. No this past winter I did not winterize it which i know it is bad because things came up and I didn't get a chance to do it but I started the motor this past weekend. The new spark plugs form last summer needed to be cleaned and it started up right away. My concerns are where water has been coming out in case i had broken anything from it sitting. Please give me any advice on what I should do regarding the motor, Thank you ahead of time.


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Daviet

Fleet Admiral
Joined
Sep 24, 2008
Messages
8,958
Re: 1974 StarCraft - 50HP Johnson Motor

I don't think you have anything to worry about from the engine sitting, the engine is self draining as long as the lower unit is in the down position. When running on the hose almost all of the water will come out around the prop, the slotted area above the cavation plate and the small stream of water aiming towards the front of the engine in the photo #3. When you run the engine the water you will see water coming out of the exhaust ports on the exhaust housing.
You will probably end up overhauling the carbs, changing the lower unit oil and by all means replace the water pump/impeller.
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: 1974 StarCraft - 50HP Johnson Motor

Try to get the muffs holding as tight as possible to the leg(I clamp mine on) to force as much water as possible into the cooling system.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1974 StarCraft - 50HP Johnson Motor

You should start off by doing a water pump job and changing the gear case oil.
 
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