1976 Johnson 115 electric help

tux16090

Cadet
Joined
Apr 26, 2021
Messages
10
I am looking for a bit of info for a 76 Johnson 115 outboard. I have posted about this before, but that was a while back and slightly different questions. At that point it was not running, but now it does run. My questions are as follows.
1. What battery do I need for this engine and is my starter bad? I hear around 500-600 CCA, but when I try to start the engine it needs way more than that. My truck has a 700 or 730CCA battery, and it took it running at 2200 RPM to crank the engine with 2 plugs in (was checking spark at the time). With 4 plugs it takes a running diesel truck (2 730CCA batteries) to crank and fire. Maybe it is my jumper cables at 20ft (4AWG), but that still seems a bit much for a 115. I hook up strait to the starter, so I don't know how that would be different from running a 1500CCA battery.
2. What is the charging capability of the engine? From what I understand it is 6A as there is not proper alternator, but I just want confirmation. I would like to run a small stereo on the boat, but I don't know if that is possible with such little amperage to charge the battery and run radio. I am not an expert in this field, but it looks to me like you can run speakers strait off of a head unit without an amp. If that's the case, could I do that, or would that overwhelm the limited power?
3. If my starter is bad and I lack power, could I switch to a starter generator, or would it be better to try and replace the starter and add an alternator? I do not know much about this, if I hadn't made that clear by this point
4. Is there a wiring diagram for this engine? I would like to know where all the wires tie back without having to tear it all apart and/or guess as to what they do. I think I figured out the key pinout, but I am not entirely sure.
5. Is there a way to test the temperature sensors, and a replacement horn for the control center?
6. This is getting a bit less electric related, but still questions I need answered. Is there a specific throttle cable I need for this engine, or is a generic Johnson/Evinrude/OMC throttle cable good enough? The plastic bits that connect on the engine broke on my cables. That's near 50Y/O plastic for you.
7. There is a linkage that attaches to the throttle on the engine, and goes up under the flywheel. Is this a timing advance, or something else?
8. While trying to run this engine, I was having trouble getting water up into the water pump using muffs. Maybe it was a lack of water as I did not turn the hose all the way on to try and save water, or a lack of pressure as the muffs are not sealing really great. I was going to run it in a large bucket of water so it is filled to the point of the pump and a bit more, but I just wanted to know if this engine need a lot of water to push through the pump and if I am on the right track.
I really appreciate any information, even if it only answers 1 question. Thank you
 

Buckischloo

Seaman Apprentice
Joined
Feb 8, 2014
Messages
48
There is a different forum here for Johnson and Evinrude motors. You may get more help there.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,422
Post the results of a compression test first.-----I would take the starter apart for inspection.-----This will establish the condition.-----My guess is that it is bad.----Easy to take starter apart if you are interested in learning a bit about them.
 

tux16090

Cadet
Joined
Apr 26, 2021
Messages
10
Post the results of a compression test first.-----I would take the starter apart for inspection.-----This will establish the condition.-----My guess is that it is bad.----Easy to take starter apart if you are interested in learning a bit about them.
I will probably just get a new starter. I opened it up and the brushes are worn, and the insulation on the coil looks questionable. I'm sure I could fix it if all the parts for it were available (they are not anymore), but I don't know what the problem is exactly and I don't want to throw money at it to find out it still does not work right. As for a compression test, I went to start it again (before removing the starter), and it wouldn't crank fast enough to start. I know its got decent compression, but that will have to wait at this point as I pulled the engine off of the boat to split the hull.
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,650
have you looked into a rebuild.. .some electric motor repair shops may help $ vs $$$ of a new one.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,422
Best to wait until the boat is repaired / refurbished.------Owner may have the funds saved by then to repair / inspect the motor.-----May even have the funds to buy a newer motor by then.
 

tux16090

Cadet
Joined
Apr 26, 2021
Messages
10
Best to wait until the boat is repaired / refurbished.------Owner may have the funds saved by then to repair / inspect the motor.-----May even have the funds to buy a newer motor by then.
I am trying to do a restore, so I want to keep the boat and engine I have. When I have the hull fixed (replacing floor and now the transom too), I will put the engine back on and finish the job. Hopefully it is just the starter and main power wires at this point. I already rebuild the lower unit and got new head gaskets, bolts, cleaned and rebuilt the carbs. As for the starter, I looked into it and if it is just the brushes, that's $20-30 and the only armature I found is $27 used. Best case its about $50 to rebuild (assuming that's the issues), I can get a used one for $30-40, or a new one for $120ish. I have plenty of time to decide, as I don't think this restore is happening before the end of this year, but I hope it does. It depends on how sick of it I get in the summer, and where I want to put my money.
My other questions still stand. Number 1 is no longer relevant, and number 8 is not entirely relevant right now, as I will just submerge the lower unit when running it now. Thank you for the replies.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,422
Wiring diagram can be found online, yes it is there..----A stator upgrade kit was available as an accessory item.----Yes that linkage advances the timing.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,422
Best to finish the boat first.----Save the beer tokens till boat is done.-----The motor work is easy.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
38,422
I think those wiring diagrams clearly show where each wire comes from and what item it connect to !
 

Crosbyman

Vice Admiral
Joined
Nov 5, 2006
Messages
5,650
It's better than nothing. I was hoping for one that would say what each wire is for. IE (this may be wrong) Purple=12V switched; Red=12V constant.
the diagram is self explanatory...
a solid wire goes a-b
a switched wire goes a... switch...b

the source (A) and the end (B) tells you what it is for and what to expect
 
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