Confused cooling question

"1975 85 hp evinrude 85593e ha

"1975 85 hp evinrude 85593e has been or is running hot, melted timer base retainer. I changed the waterpump when i got the boat as a precaution. Verified that the hot horn works by grounding it and it works fine. I have never heard it till i checked it.
I have read previous post and i am confused where exactly is the water should be exiting the motor. Is it the holes above the cavitation plate or the two holes coming out from underneath the motor. I have never seen anything more than a mist or spray of water coming from the two holes under the motor. Nothing like i'm used to seeing when my mercury "pees". Whereever it is supposed to be exiting can i test it on muffs or will it need to be in water?
I have been told to replace thermostats but i cant find them in my manual or parts diagrams. Does this motor have thermostats and if so how many and where? Is there a way to check the function of them?
Thanks to all who has answered me in the past couple weeks and those who continue to answer me. Thanks to the knowledge from this discussion board ya'll have helped me tremedously."

"Go to ------shop.evinrude.com

"Go to ------shop.evinrude.com------ there you will find the pretty pictures of your motor.You will find the thermostat ( may be called a " vernatherm " ). If one of them pissers makes you feel good, then put one on your motor as it is not hard to do."

"In exhaust housing, see attac

"In exhaust housing, see attached pick.
Be sure the system works and thermostat and valve works, or You get an air-bubble on top of cylinder that may cause local overheat.
"

What are the two holes under t

What are the two holes under the motor. They have the two rubber hoses attached ? Should water be coming out of these? How do i check if system works? Can i take apart and check or will i need to get gaskets before disassembling.

"I guess You are talking about

"I guess You are talking about the rubber hoses leading water to the thermostat housing from the engine.
Take the thermostat/valve system off, clean all parts, be sure valve seats and seals and all parts are there!!!!
Use new gaskets and new thermostat at assembly.
When engine runs at low idle it should be even in temp on both cylinder banks and barely to touch."

"Mike.... The holes just above

"Mike.... The holes just above the cavitation plate are the thermostat water outlet holes. When the thermostat opens, water will flow out those holes.

The two holes that you see on the outside of the engine, at the rear portion and just below the powerhead are the exhaust relief outlet holes, explained below.

(Exhaust Relief Ports - Exhaust Housing (Inner/Outer)
(J Reeves)

The long housing between the powerhead and the lower unit is called the exhaust housing. There is a inner housing within it that has a heavy duty seal around the bottom of it, or heavy duty seals around a inner extension between the housing and the lower unit.

The red hot exhaust travels down thru that inner tube and out the propeller with a somewhat supply of water to cool the propeller hub. A good amount of water surrounds and fills the space between the outer and inner tube, otherwise the outer housing would get so hot that the paint would burn off.

Some water pumps, for some reason (differing even when new) exert a great amount of water pressure, and if the exhaust housing seals are in perfect condition, the water fills the tube to a point of overflowing.

This brings into play those two holes or slots, whichever the engine might have, at the top rear portion of the exhaust housing just below the powerhead.

Now, if those two holes/slots weren't there, water would continue to flow up into the cylinders. Water not flowing out of those holes is no concern for alarm UNLESS that outer housing suddenly becomes extremely hot..... the warning horn should sound long before that happens.

The main reason for those holes being there (exhaust relief holes) is that when at an idle, there is an extreme amount of resistance encountered by the exhaust trying to escape due the fact that the outlet via the propeller is now blocked by a wall of water. The escape route in this case is for the exhaust to escape out those two holes, otherwise the engine would slow down quite quickly and die. If exhaust cannot escape, air/fuel cannot gain entrance to the engine.

When time permits, visit my store at: http://stores.ebay.com/Evinrude-Johnson-Outboard-Parts-etc?refid=store

The majority of the water exiting the engine flows directly out thru the propeller.

Thermostat..... The water flows up thru the powerheads various water passageways, then thru the cylinder heads to those two rubber hoses. The other end of the hoses, as Morten states, connect to the thermostat housing. Follow Morten's advice as above.

Since the overheat warning horn functions, it should sound off before the engine reaches any temperature that would be harmful to the engine. Are you sure that it is overheating OR is it just that you don't see any water exiting the engine as you think it should? You can have a water telltale outlet installed on that engine if you like to give you peace of mind."

"At this point i'm not sur

"At this point i'm not sure if its overheating. My timerbase ring was melted so thats why i'm wondering about overheating. The longest ive run it so far has been an hour staight. I checked engine then and it did not seem hot just warm to the touch. I have spent alot of money and time on it in the past couple weeks(stator,rectifier,coils,powerpack and now timer base ring) and i dont want to risk screwing anything else up.
According to what ive seen i need to order (1)thermostat and (2)gaskets, correct?
Also, thanks guys!"

"If you've been running th

"If you've been running the engine and have encountered no overheating problems, I would assume the timer base retaining ring was melted by a previous overheating problem before the engine came into your possesion and that the overheating problem was corrected at that time."

"I believe i'm going to re

"I believe i'm going to replace timer ring and just keep a careful eye on it. I have noticed that the # 2 cylinder's paint looks a little darker like it has got hot, maybe it was the culprit at one time. I've also noticed that the hot horn sensor is on the othe side. How does that work? Water temp? Can it tell if the other side(#2) is overheating. Also how would i install a "pisser" to help me keep an eye on it.
Thanks joe for your detailed input. I think its awesome you guys share your expertise and knowledge. If anyone ever needs advice on autobody, frame or paintwork let me know.
thanks again!"

"Yes, that timer base retainin

"Yes, that timer base retaining ring needs replacing.

Overheat warning sensor on the other head? The 1975 85hp moderl only incorporates one overheat sensor. You'll need to elaborate somewhat on that aspect.

Installing a "water telltale outlet"..... I'll leave that to someone else. I don't get into those conversion areas."

"Yes, i know it only has one.

"Yes, i know it only has one. My question was if the #2 cyl was overheating how does the sensor(which is on the opposite side at the #3cyl) know that it is overheating. Does the sensor work off of water temp or metal temp?
Also i started the motor today and run it on muffs in my druveway for about 15 min. I did observe water coming from the holes above the cavitation plate and the exhaust. The water was warm. After shutting it off i felt the heads and each one was only slightly warm to the touch. Yhe hoses coming from the thermostst was cool. Really not even warm. Does this sound like everything is working? Was 15 min running even enough time for it to get hot? thanks!"

"Sounds like the thermostat mi

"Sounds like the thermostat might be stuck slightly open. The heads, after 15 minutes, should be fairly hot but not excessively hot.

I thought you would know there was only one overheat sensor but I had to ask. You asked "Does the sensor work off of water temp or metal temp?"

Answer = both in a manner of speaking. The sensor is situated in a metal cup of sorts. The water heats around the cup and conducts the heat to a metal portion of the sensor."

Is stuck slightly open cause f

Is stuck slightly open cause for alarm?
Also i was studying the parts diagram and saw the exhaust seal. I remember when i changed the water pump that this seal was not in good condition. i couldnt find it in the lower unit diagram (duh!) so i reused it. It wasnt completley destroyed but it wasnt in good shape. could this cause problems .

"Tell tale:
You may install a

"Tell tale:
You may install a 'tell-tale' in the rear exhaust cover. Be sure You even install the restraining nipple in the lower cover as well, or the pressure valve in the thermostat system might be affected.
If possible, have a look at the newer 90/110/115 models and 'copy' the set up."

"Mike:
If the seal is in bad

"Mike:
If the seal is in bad condition, it might cause exhaust to leak into the water pump and reduce it's capacity or in worst case fail!
If the thermostat/pressure valve is open, the block might not be completely filled with water (depending on pump condition and rpm), You may get an air pocket on top of engine with a local overheat problem, melting the plastic ring for ignition(!), but it will not set off the alarm as the switch will read 'cold engine' due to cold water rushing past at the lower level.
It is all a funny chain reaction.
Bottom line:
Get new seal, check/fix Your thermostat system."

Parts lists a "vernatherm

Parts lists a "vernatherm " And a "vernatherm valve" do i need to replace both? Is there only two gaskets i need to do the thermostat. if i'm going to have to get an exhaust seal i might as well get it all.

"There are two ways of doing i

"There are two ways of doing it:
1: Rip it down and check what parts You need -then order.
2: List all possible parts needed and check with Your dealer/supplier about availability and delivery time -then take down and order what You need.
If the engine has been in salt water, it might be some 'surprises', and You do not know if a previous owner has 'removed' some parts as a 'temporary' solution.
In both cases You do not know what parts are needed until You have had a look at it."

Tommorrow i will rip it down a

Tommorrow i will rip it down and see whats up. If everything is there how do i know what needs replaced?

"If in doubt, take some pics a

"If in doubt, take some pics and post."

"Thanks morten. you've bee

"Thanks morten. you've been a great help. Check back tommorrow, i know i'll have questions."

"this is a pic of my thermo <[

"this is a pic of my thermo thermo

"Hey guys! heres my mess. I&#3

"Hey guys! heres my mess. I'm guessing the wads of melted plastic. Looks like i need two seals, springs, two gaskets, "vernatherm"??? does it look like all the pieces are there? i'm not sure i understand quite how this works. Does the "vernatherm" just slide out of the housing?"

"Yes, the vernatherm simply si

"Yes, the vernatherm simply sits into that housing. Replace all of the melted and damaged components,including gof course the vernatherm.

My guess is that someone in the past replaced the water pump assembly BUT did not bother going into the needed additional repairs that you're into now."

Would it be a good idea to run

Would it be a good idea to run water through the heads to maybe flush anything out or is that a bad idea?

"I assume you mean to force wa

"I assume you mean to force water up the water tube and let it flow out the bottom of the cylinder heads where the rubber hoses would normally be attached. If so, that's okay BUT do not allow water to come in contact with the electrical components, especially if the battery is connected as even with the key in the OFF position, voltage is present at the starter solenoid, the rectifier assembly, etc."

The pic says the most!

The pic says the most!

"Here is my question: <[img]"h

"Here is my question: thermo"">


Hey guys ! I got my parts today. I'm confused about the relief valve. According to the diagram it looks like the valve goes in the thermo housing. I tried to put it like the diagram but it didnt look right. The way i have it in the picture the bevel on the "spacer" matches the valve. But the way i have it doesnt match what the diagram says. My common sense tells me i have it right but i dont want to get in trouble!Does this look correct?"

I know it looks right accordin

I know it looks right according to my previous pic of my old one. But since it was all melted i thought i needed to double check with someone with some experience.

It does not look " right &

It does not look " right " to me.If you get no other help I will look at one of my motors to confirm how it should be.

"Joe, I have a similar problem

"Joe, I have a similar problem with my 1978 johnson 115,I got it out of storage this year and prep'ed it for the season like always I put the muffs on and started it.I noticed a large amount of water coming out the exhaust relief holes that I dont remember coming out before.It takes about 40 seconds to come out when first started then continues to come out.It doesnt overheat,runs fine and starts right up,could my thermostats be stuck open causing to much water to enter the cooling chamber between the 2 exhaust housings or am I looking at a more serious problem?"