1977 model #115793S Evinrude 115hp

[flathead6990]

motor is overheating need help with this ventotherm problem?? Is this the cause?? How do I test this ventotherm??

 

[Bosunsmate]

Re: 1977 model #115793S Evinrude 115hp

test it like a thermostat in water big heated, that it opens and closes ok. Check that that check valve moves smoothly inside the black grommet too

 

[flathead6990]

Re: 1977 model #115793S Evinrude 115hp

test it like a thermostat in water big heated, that it opens and closes ok. Check that that check valve moves smoothly inside the black grommet too

Thank You. I did check the ventatherm in hot water & the pin moved foreward and in cold moved back. ;-) The check valve appears to move/push in on the spring pretty easy top hole in the picture. I didnt find a black grommet though. Did you mean the gasket or maybe the metal housing?? Does a check valve just push in or is it supposed to spin?

 

[Bosunsmate]

Re: 1977 model #115793S Evinrude 115hp

Maybe it spins but if it pushes in thats good.
I think its a blackgrommet it sits in there but either way so long as its not suck that good and it doesnt look deformed by heat.
Is there a good telltale stream?
Are the plugs normal or rusty looking (look at them before starting up after its sat overnight or longer)

 

[flathead6990]

Re: 1977 model #115793S Evinrude 115hp

Maybe it spins but if it pushes in thats good.
I think its a blackgrommet it sits in there but either way so long as its not suck that good and it doesnt look deformed by heat.
Is there a good telltale stream?
Are the plugs normal or rusty looking (look at them before starting up after its sat overnight or longer)

Thank You. The ckeck valve pushes easy & no black gromet located. It does not appear deformed. The lower one with the thermostat pushes but a lot harder to push the lower one.

The spark plugs are dry, tan, and gapped .030. Do you think The next thing I should look at is the water deflectors on each side under the piston covers on each side?? My motor does not have a tell tale. I pulled the water hoses connected to the bottom of the piston covers and both had a steady water stream coming from them. Not like dripping or shooting out either but steady on the muffs but also I only had the water on 1/2 way not full blast.

 

[Bosunsmate]

Re: 1977 model #115793S Evinrude 115hp

What makes you think its overheating?
Has your imepeller being done recently?

 

[flathead6990]

Re: 1977 model #115793S Evinrude 115hp

I was out last Friday night & my overheat alarm went off & my thermostat pin was pegged. Trolled back in & took my wife for a spin Saturday & it started to overheat again. see my thread (evinrude 115hp model # 115793S) got no replies so started this thread.
No I havent ever had my impeller done in the 8 years Ive had my boat. I am handy but terrified to mess with disconnecting my lower unit. I am not sure how to disconnect & reconnect the linkage in there. Dont have the $ to take it to a boat shop here in Arizona to get it done ( they rip one off for labor here). So I was hopingit was something I could easily fix. No manual on my motor anymore due to it getting soaked a couple of years ago. :-(

 

[Bosunsmate]

Re: 1977 model #115793S Evinrude 115hp

You need to get that impeller done, as even if it isnt causing your problem it will be due to crack soon and send parts up your cooling tube, then you really will have lots to do on it.
Is there are gear link coming out under the carburettor?
Those bolts should all back out easy on the gearcase, ive never encountered problems there about getting them to back out.

 

[Bosunsmate]

Re: 1977 model #115793S Evinrude 115hp

Its a real easy job, all you have to do is make sure you get that connector on top of the shift shaft disconnected.
Then undo the bolts and carefully back it out.
Post photos if you arent sure what to disconnect, many people on here will show you what to do

 

[flathead6990]

Re: 1977 model #115793S Evinrude 115hp

There are two carbs on this motor.I did the rebuild on them a few years ago. I will pull them probably tomorrow & see if I can locate that connector on top of the shift shaft. I was given a link to explosion of parts diagrams from that other thread & they have helped me a lot. I will try & post photos (since I figured out how to finally do that today). Hope you will take a look at this thread from time to time. I really appreciate the help from everyone. Of course I still need to order the impeller & ventatherm & gasket(s).

Since I am going to tear into this I will probably pull the heads & check the deflectors too. Or think maybe I should just get gasket for the ventathem housing cover & fix/replace the impeller & see how she runs?!?!? ;-)

 

[Bosunsmate]

Re: 1977 model #115793S Evinrude 115hp

Up to you, depends how much you want to spend.
Headgaskets are about $12 each.
If you do that you may as well clean by the rear water cover gaskets they are about three dollars each