1978 Johnson 70hp

[JeffSmith]

So I just picked up a 70hp Johnson Sea-Horse today. I will tell you all what I know about it, and if anyone can tell me anything else about it, I would appreciate it!!!

model: 70el78c
serial: J4939093

I know it is electric start, 50:1 two stroke, and a 3 cylinder. I guess that is all I know about it, aside from 70hp...

Also, it's got some heavy black plastic fins bolted just above the prop (hydrofoil I believe?)...what is the purpose? If I trade this motor for a smaller one, which I would prefer to do, should I take this off and use it on the other motor (are they universal)?

Sorry if these are all ignorant questions...I am trying to learn here, and I appreciate everyone's patience.

Any info is greatly appreciated!
Thanks
Jeff

 

[Whoopbass]

Re: 1978 Johnson 70hp

That is a hydrofoil. You can put it on a smaller outboard down to around 40 hp or so. Some people like them and some don't. All they do is help you plane faster.

Unless you have a small boat its better to have more horse power so you might want to keep that motor.

Install that motor and see what you got.
Those are good motors. Just search this forum and you will learn alot about it.

 

[JeffSmith]

Re: 1978 Johnson 70hp

I do like the idea of more power...what guy wouldn't!! But my boat is small (14ft tri-hull), and has a max rating of 55hp. If I was still young and reckless, it wouldn't be an issue, but I have a family now. My intention behind getting this boat is to get the kids out on the lake as a family and just enjoy life...I don't need a big engine to do that! After I learn more about boating...then I will get something bigger and better!!!

 

[sammy d]

Re: 1978 Johnson 70hp

my 70 hp motor starts fine and idles fine but when i try to put it in gear it just dies any sug. thanks

 

[jtexas]

Re: 1978 Johnson 70hp

sammy d, welcome to iboats, but start a separate thread.

state the year and model #, also, how long your motor's been like that, and what recent maintenance you've done. Compression if you have it.

 

[ritchie_bones]

Re: 1978 Johnson 70hp

i just bought the same motor and have been told its a good motor--mine runs great after warm up and trolls like a 4 stroke-