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1975 Johnson 115 Overheating Horn

N

newram05

New member
"Ok I just bought this boat fr

"Ok I just bought this boat from a buddy of mine, he stated he replace the waterpump, and the vernatherm. Started it up yesterday and after about 15 min at idle warning horn came on again. Shut it down immediately. My questions are, Do these have 2 thermostats? Where can I find a diagram of my exact motor? What are some other thing I can check?
Thanks"
 
welcome to marineengine!!

s

welcome to marineengine!!

shopevinrude.com has the best exploded diagrams and complete parts descriptions.

and yes i think it should have 2 thermostats side by side

could be dirt dobbers or something else stopping up some passages.

was the old impeller in tact?
 
"Thanks,
I'm not sure ab

"Thanks,
I'm not sure about the impeller, I'll ask my buddy tonight and see what he says about it. I've got the shop manuel for this motor but it doesnt mention thermo's at all. I'm going to study the diagram tonight and see what I can find.
Are there any forums with pictures that others have taken to show where the thermo's are? Hoses that could be clogged? Or any work they've done on this engine?
Thanks"
 
"Ok, my friend says the impell

"Ok, my friend says the impeller is new also. so here is a new parts list:

Waterpump
Vernatherm thermostat (1)
Impeller

Where can i get a diagram or more illustrational book on this motor?"
 
"make sure the two smaller hol

"make sure the two smaller holes in the thermostat housing are not plugged up with sealer.they allow te air to bleed off,if not the water will not prime up into the system"
 
"If so equipped, check oil lev

"If so equipped, check oil level in remote oil tank. Low oil warning uses the same alarm. Just a thought."
 
overheat is constant beeeppppp

overheat is constant beeepppppp................
low oil is beeeppp ...... beeeppp ..... beeepppp...
 
"his wont have the oiling syst

"his wont have the oiling system,.and they do,use the same horn,but diff signals..quick beeps,beep every 20 seconds,or continuous."
 
"Well today we hooked up the m

"Well today we hooked up the muffs and she ran strong and cool, no horn! but noticed that water was seeping from head gaskets!! pulled them and noticed blown gaskets, heads and pistons looked good, no cracks but just a little scoring on one cylinder! What to do? Cheap, dont want to spend a lot of money!!"
 
"new hd gaskets....clean all s

"new hd gaskets....clean all surfaces very well,.use a little gasket sealer on those gaskets."
 
"Ok no overheating, but now it

"Ok no overheating, but now its like we have no power, wide open only at like 600rpm? going to do a compression test! Any other ideas? didnt make it very fast kind of disappointed but at least it runs and not overheating..."
 
"clean/rebuild carbs---every t

"clean/rebuild carbs---every tube/jet/orifice...
spotless..clear...new plugs,...ck for 7/16 spark on all 4....ck that rotating timer piece under flywheel,is advancing all the way,upon wide open position,and that carb butterflies are both wide open,at wide open,position."
 
the carb butterflies are open

the carb butterflies are open all the time. Should there be a cover on them? should they open and close with the throttle? Mine stays open all the time with no cover on them
 
"Ok i've got a question? T

"Ok i've got a question? The guy I bought this off of says when he dropped the lower end to replace water pump he had the throttle all the way down and dropped it. Now my question is do I have to have the throttle all the way down to install it? We installed it while in neutral, would that starve it for power or does it matter what position the throttle lever is in when lower unit is dropped and intalled???"
 
"you say butterflies are alway

"you say butterflies are always open,the butterflies
i am sure are the choke b flies,they close when you choke it,the throttle b flies are behind those.
now i reference to your other post no it does not matter what gear its in/its an out board not a stern drive,sometimes its easer if the shift rod is up for re installation,but not required"
 
"On the high hp engines, runni

"On the high hp engines, running on a flushette, be sure to have that water hose running full blast."
 
"well, we decided that we were

"well, we decided that we were going to change the gas. It was the same gas that he put in last year. (stale gas) Ran it and still same no power.. then decided to clean spark plugs and check gap.... WOW.... it runs good. ran at about 30mph....impressed... now how do you adjust the Idle? It starts hard and when putting in drive or reverse it stalls unless someone is on the back giving it throttle. Also we solved the overheating by just taking out the verna therm. is that going to cause problems?

It was a great second day of trying to run this boat... ran out of gas and drifted a while with no ore's and finally got a tow and waited till 11pm for gas to arrive from a buddy!!! Good Times!"
 
"changing gas and cleaning plu

"changing gas and cleaning plugs worked, ran like a champ. hit 30mph!! Now want to rebuild the carbs and I cant seem to find the right part number? Anyone know what the part number is for a rebuild kit??"
 
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