1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Mercnewguy

Seaman
Joined
May 11, 2013
Messages
59
Finally got some time to get this old beast hung and hooked up to the boat. Got it all set and fired it up today and it fired up great, especially for how long its been sitting. However I had to immediately shut it down because I saw/felt NO MIST coming from the two "pee holes" out the back. This motor sat for a few years before finding its way to me so I'm thinking the water pump needs a rebuild. While I'm at it I plan on changing the drive shaft seals underneath it as well as the prop shaft seals. Anything else I should change while I'm in there? Do I need to change the thermostat, and according to the picture is the thermostat what my arrow is pointing at on this engine? Seems like an odd place.... arent they usually at the top???
thermostat 1.jpg

What components do I need to replace when I change the thermostat?

Next question: I saw a small leak in my fuel line to my upper carburetor and want to replace it. Anyone know what size fuel line it is off hand? My manual doesn't say the size.
Fuel Line.jpg

Last but not least how do I get this dang shift rod to release? I can see it under the carbs but can't figure out how to disconnect it???? I see the big bolt on the shift linkage but what else needs to be done and in what order? Do I have to disconnect anything from the lower unit on this motor?

shift link 1.jpg

shift 2.jpg

Thanks for your help getting on the water everybody!
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

I can answer two of them.
Yes the vernatherm is under there. Its being superceded by a thermostat 18-3560
You can take the fuel hose off and measure it.
Actually i will have a shot at the third, loosen that bolt and see if you can pry those arms off the shift rod
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Also change the gearcase oil and impeller and sparkplugs then you are as good as can be
 

Mercnewguy

Seaman
Joined
May 11, 2013
Messages
59
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Thanks Bosunsmate. I drained the gearcase oil last week and it was looking milky thats why I want to change those shaft seals. Do you guys think I need to buy the whole water pump kit WITH the housing or WITHOUT the housing with just the wear plates and o rings and impeller? Thanks.
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

get the whole thing if you have the spare cash. That way you are set for a lot of hours.
Very hard to tell how worn the current one is.
Ideally what you should do is replace the water deflectors and clean out the channels in the head and water cover.
And shave a bit off the head with sandpaper stuck on glass.
The water deflectors eventually crumble and can do all sorts of nasty things when that happen.
If you replaced all of those things you would be as good as could be with a unknown history motor
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,031
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Use a 5/8" wrench and take the bolt out---Seperate the arms to release the shift rod.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

A really clean engine, for it's age! Regarding the mist from the exhaust relief ports. There is a mist which will come out of them-but only after the vernatherm (thermostat) opens. So, it may start and run, even pump cooling water. It may take a minute or so for the stat to open and the misting to start-that's normal. Once started, hold your hand back by those ports. Once they open, a water mist will form on the palm of your hand. Your engine may be cooling properly...still, I'm with you-best to replace the pump, and vernatherm so you know when you go boating, that you won't have problems out on the water. Be careful replacing the leaking hose. That is a factory special, heat-formed to bend in a 90. Sold originally under part number: 324078 (2 per engine) Supercedes to 2014 hose: 333385 I'd get the factory replacement. Bulk hose will tend to kink when bent in a tight turn, causing a fuel restriction. FYI, all original hoses on the engine (if any are left) are not rated to handle ethanol fuels. The innards of those hoses will start to break down and black bits of hose will migrate downstream into the carbs and jets, causing potential problems. Best to replace any original hoses.
 

Mercnewguy

Seaman
Joined
May 11, 2013
Messages
59
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

This is why I come to the pros. Thanks guys. emdsapmgr is that 333385 2014 hose an alcohol resistant hose or is the 324078 hose better? Can you tell me which parts of the vernatherm need to be replaced? The metal thermastat, the plastic vernatherm and gaskets? Anything else? Bosunsmate are you referring to the hoses going up to the heads as the water deflectors that need to be replaced or any other components? I can't seem to find their part number on any of my exploded diagrams?

Thanks again!
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,031
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Cylinder heads have to be removed to find the deflectors.----They are wee hoses inserted into the block.---Water does NOT go through these hoses.------These hoses guide water around the block for proper cooling.---They are important !
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

They are part number 0318357 deflector, 4 required.
The head gaskets are $13 each so if you can afford that and the deflectors its something that will significantly improve its reliability. When those deflectors get old they crumble so water can stop circulating properly and the top of the head will start overheating.
Also the crumbling deflector can block other parts in the motor slowing cooling too.
 

Mercnewguy

Seaman
Joined
May 11, 2013
Messages
59
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Thanks for the replies. I was getting ready to order some parts and double checked the serial number and actually found this motor to be a 115493B 1974 model. I still ordered those hoses emdsapmgr because I could not find anything that was specific to 1974. I'm hoping that those 333385 hoses will fit... The part for 1974 is 0319740 but I can't find it anywhere. What are the parts I will need to replace the thermostat and do you think its necessary? Thanks.
 

Bosunsmate

Admiral
Joined
Apr 7, 2012
Messages
6,129
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Im not up with the play on vernatherms but i suppose you might be able to put it on a bit of wood and heat it up in a suacepan of water and check that its opening. Replace any gaskets undone when getting it out
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

You are correct, the 74 carb hoses are a different number: 319740. It supercedes to this factory # 324079, an 2014 EPA compliant hose. I'd plan on replacing the vernatherm for sure-for now. Once you get the thermostat housing apart, examine the nylon valve in the housing-check to see if it shows any heat-related deformity. If so, then order a replacement. New thermostat gaskets for sure. FYI, that vernatherm runs much cooler (maybe around 115) than the later thermostats (rated at 143 degrees) Current vernatherm part #384719 You may be using the factory parts lists for help: epc.brp.com The exploded parts diagrams are helpful when trying to figure out how it works.
 

Mercnewguy

Seaman
Joined
May 11, 2013
Messages
59
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Thanks for getting back to me so quickly and for all your help. You are great to help out. I had already ordered that 333385 hose and it looks to be the same as that 324079. Is it in fact the same hose? They look identical but will they work interchangeably or should I hurry and cancel my order and try to find the 324079 hoses? Also is there a thermostat kit that they sell anywhere that you guys know of? Seems they make a kit for every other motor and year but this one.

Thanks
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

The hoses are probably very similar. Possible that the hose is either longer, or shorter on one leg or the other. In any case, likely they will work fine. The factory does not make a thermostat "kit" for that engine.
 

Mercnewguy

Seaman
Joined
May 11, 2013
Messages
59
Re: 1973 Evinrude 115 rebuild please help! Thermostat, water pump, fuel lines.

Thanks everyone for your help and guidance. I have ordered some new fuel lines, a new water pump kit, and a vernatherm kit. When these parts get in and when I get some time I will install these parts and take pictures along the way to help anyone else working on these fine motors.

Thanks!
 
Top