New Member/ Just picked up a 15' Terry Bass Boat/ Have some questions

Hi all, New to this site.
I recently inherited a 15' Terry Bass boat with a 70 hp Johnson Sea Horse.

Let me start with this.
The boat sat up for 4 years in the yard.
I got it to my house, dumped the fuel, put good fuel in,
Installed a new battery and it took a bit but it started up and ran.
Rough, but it ran.
I plan on doing a some maintenance on it but have some questions
that maybe you guys can help with.
I have a carburetor guru that is going to clean the carbs for me.
My questions are.....
1. How do I find out what year the motor is. I think it's somewhere between
1976 & 1982.
2. Where can I find a diagram of the engine.
3. How do I access the water pump because I was told they dry rot.
4. Where is the best place for online parts.
5. Is this motor a 2 or 4 stroke, and what oil should I use.

Well, that's what I can think of for now but I'm sure as I get it water worthy,
I'll have more questions for yall.

Thanks,

Don

 

Welcome Don,

Look on the transom mount for the Johnson's model and serial number.
It's a 2-stroke
A manual is a good investment - http://www.marineengine.com/manuals/johnson/

 

Yeah, I forgot to post back that I read up on boat.net where to find the model number plate.
I picked up a service manual for $5 bucks.

Its a 1979 model
Now I'm reading up on how to pull and replace the water pump.

 

It won't be complicated at all once you have the manual to refer to. Everyone should have the manual for their motor. Follow it step by step and do it exactly - even though it's simple enough, trying to wing it and figure it the tiny detail, a gasket or oring, sometimes wastes more time backtraking or contemplating than the whole procedure. Also if anything is stuck with age, be persistent and keep a slow, careful approach until you get it loose.

 

Yeah, I've been reading up on how to do it.
Seems pretty easy, I'm used to doing maintenance out of a service manual.
I have 2 motorcycles that I do all the work on myself.
A Kawasaki Ninja ZX10R (1000) and a ZX6R (636)
I have a rubber mallet for some gentle persuasion if needed.
I plan on having the carbs done by a buddy who is a master with any kind of carb,
and changing the lower unit oil and spark plugs and water pump myself.
Also gonna lube all cables for steering and throttle too.
Going over the electrical system to make sure all is good there too.

 

First thing I'd do is check the compression, making sure to follow the manual instructions so as not to damage electrical components. If there is a major difference between cylinders, the thing won't be much use until investigated and rectified. When you get to the stage of dropping the gearcase off it to service the water pump, pay close attention to the screw connection of the shift rod to the engine linkages, it can be tricky getting it to align properly when re-assembling, unless you follow the instructions regarding what gear to be in, etc.

 

Rodger that, I can get a compression tester from Autozone.
Preciate the tip on the screws on the shift linkage.
I'll take some pics and video of the position before disassembly.

I have a dry erase board that I'm taking notes and keeping track of each task with.

 

You sound as though you have a methodical attitude, which will come in handy. One thing about working on the older engines is they don't require a lot of specialized knowledge or equipment, and common sense gets you a long way. You have one of the classics of outboard design, so worth the effort to restore.

 

Thank you, having several modern sport bikes, I have to be methodical.
I do my own valve adjustments and such and keep meticulous notes and records.
This motor was running good before it sat up I was told, so I doubt there will be any compression issues. Just a good carb cleaning and some new plugs and gear oil and water pump should do the trick and have it back up to par.

One thing I have learned is to do all the research and read read read before tackling a new project.This older engine looks to be a breeze to bring back to life.
I always appreciate any and all input from those who have been there and done that ya know.

P.S.Here is a pic of my bike.