I bought a used 1973 115HP Johnson !!

[jddenham]

Hi All,

Looks like I will be replacing my 50HP Mercury with a Johnson:

http://cgi.ebay.com/ws/eBayISAPI.dl...90030952424&rd=1&sspagename=STRK:MEWN:IT&rd=1

Going to go on my old 16' V-hull:

http://www.james.denham.com/Web photos/boat.jpg

Anyway - just wanted some feedback on my purchase and any tips or thoughts on setting the 'new' motor up!!

Would anyone know an approximate shaft length for this motor? I have a jack plate I can use, since my transom is only 16".

Cheers,

James
www.james.denham.com

 

[Joe Reeves]

Re: I bought a used 1973 115HP Johnson !!

The portion of the transom brackets, the part that would sit upon the transom.......

Measure from there down to the cavitation plate that exists just above the propeller.

A measurement of approximately 20" would indicate a long shaft engine.

 

[Indymike]

Re: I bought a used 1973 115HP Johnson !!

Nice motor. I have one just like it. Just wish it had tilt& trim. Lots of info here on the set up. Check out the prop forum too.

 

[tashasdaddy]

Re: I bought a used 1973 115HP Johnson !!

nice boat, should be a much better match. get back when you find out the shaft length.

 

[papasage]

Re: I bought a used 1973 115HP Johnson !!

git a C M C add on . if the motor blowa you can just add another motor 8)

 

[jddenham]

Re: I bought a used 1973 115HP Johnson !!

It is a 20" shaft, so I will be installing a manual jack plate that I got off ebay:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=230017653952

I will start with the cav plate about an inch above the keel since it's setback a little. Sound good?

Now that I have enough power I probably don't need the old stingray hydrofoil either?

 

[Scaaty]

Re: I bought a used 1973 115HP Johnson !!

I dunno, I looked at your pic links, and, well, I would SERIOUSLY study your set up. You have a standard 16 foot family runabout with a 50 horse now. That transom aint new anymore. Now you want to slam a 115hp on it, AND on a extended Jackplate to boot? I think the first time you nail it, those controls at your right side will dissapear.....along with the motor. Wear a life jacket ...think you will need it

 

[jddenham]

Re: I bought a used 1973 115HP Johnson !!

Very good thoughts to consider!

The boat was made for a 125HP motor, so the 115 shouldn't be a problem, as long as the transom is solid.

As far as the jackplate goes, maybe that would change things. Maybe I would need a reinforcing plate or something?

I am brand new to boating this year, and this boat is sort of a learning experience. Any ideas or advice is appreciated.

I plan on doing a new floor in this boat to add storage and an under deck fuel cell. It will also be a low risk project since the boat itself is relatively worthless.

I can always junk this boat and sell the motor, or put it on another hull.

James

 

[Scaaty]

Re: I bought a used 1973 115HP Johnson !!

Just make sure the transom is in decent shape, then, what the hell, have at it! I've been known for 150hp on stuff that needed more hp, of course, more is still never enough. Good luck, take some pix when its done.

 

[Theoutdoorsman]

Re: I bought a used 1973 115HP Johnson !!

jddenham.......... Just a little forethought for ya. I'd seriously consider reading over the "To Wake a Sleeping Outboard" in the frequently asked questions forum. Might accidently save you a lot of missery in the near future. After all, you have no prior knowledge as to the upkeep of this motor. A good decarb would be a MUST in my opinion (also in the FAQ forum). You got a good deal if the compression is good on all four cylinders. That should be a really nice addition to your boat. You'll notice the difference. Just be sure you prop it correctly. Best of luck to you................... ALAN

 

[clint]

I bought a used 1973 115HP Johnson !!

With the transom solid it sounds like a go. Just mount the jack plates very carefully and make sure you have some square plating for the inside when you bolt brackets on for extra strength. If you don't have trim tilt make sure also to have engine release free in case your motor hits bottom. This way it will not weaken transom. Good Luck!
Clint 8)
Also I have to comment on Indymike's rebuild on his boat and motor,,What an awesome job he did,,,8)

 

[jddenham]

Re: I bought a used 1973 115HP Johnson !!

I made the 18Hr round trip to get my motor finally!

It looks pretty nice for it's age.

I ordered an OEM manual off ebay for it today, but until I get it, I have a few questions:

What are these holes:

http://www.james.denham.com/Web photos/jfoot1.jpg
http://www.james.denham.com/Web photos/jfoot2.jpg

I have a bunch more questions but should probably start threads for each one?

General quirks/tips
Use of trim pin
Lever on transom mount
Running on muffs
Battery and electrical precautions
and more . . . .

 

[ezeke]

Re: I bought a used 1973 115HP Johnson !!

Water drains. Keep them open.

 

[tashasdaddy]

Re: I bought a used 1973 115HP Johnson !!

thoses are relief ports.

 

[ezeke]

Re: I bought a used 1973 115HP Johnson !!

Great- "relief port". What the deuce does that tell you about function?