1958 7.5 hp johnson

baconbiscut

Petty Officer 1st Class
Joined
Jul 11, 2006
Messages
364
Well I just got this engine today from a fella that I helped out on the water a few weeks ago and the paints faded and the engine seized. I have high hopes for this motor and hope to get it running but it needs alot of work. I dumped some TCW 3 oil into the spark plug holes and layed it face i think thats the right way to do it. lso is there anything I should know about this engine before a take it apart and try to fix it. The motor seems like on of those motors you look at and lose all determination to fix it. but I think i can get it running. Anyway I don't know what I will do about painting but but i was think a nice johnson white because if I paint red I won't to use. Well what do you guys think.
 

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1958 7.5 hp johnson

Worry about the seizing issue before you choose what color to paint it! Any seized engine really ought to come apart for inspection and proper repair. Simply dumping oil in it may free it up, but most of the time it doesn't actually fix anything. The life span of a freed up motor is usually measured in minutes.

Those old 7.5s are great little motors and it would be well worth putting a little time and money into it...

- Scott
 

BoatBuoy

Rear Admiral
Joined
May 29, 2004
Messages
4,856
Re: 1958 7.5 hp johnson

The engine might not be seized. I think that has the spring shock absorber on the drive shaft, that, when broke, will not allow the motor to rotate.
 

wbeaton

Commander
Joined
Jul 30, 2006
Messages
2,332
Re: 1958 7.5 hp johnson

Do both of the above. Separate the lower unit from the motor and try to turn it over. If it still won't turn over then its the powerhead. If it does then its the lower unit. Either way, one of them will have to come apart.
 

baconbiscut

Petty Officer 1st Class
Joined
Jul 11, 2006
Messages
364
Re: 1958 7.5 hp johnson

I attemped to pull the lower unit off but when I unbolted it I got it to come about half an inch down but no further I figured I was doing something wrong so I bolted it back on. Anymore advice
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: 1958 7.5 hp johnson

You have to remove the powerhead first in order to disconnect the shift rod before you can get the lower unit off. By the time you get the powerhead off, you will already know which end the problem is in.
 

baconbiscut

Petty Officer 1st Class
Joined
Jul 11, 2006
Messages
364
Re: 1958 7.5 hp johnson

Thanks alot I'll get to it and tell how it goes. Oh and are the 5.5 hp models lower units the same as the 7.5 hp models lower units.
 
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