termostats

[asok]

Hello,<br />where do I find the termostats on my engine? I have a evinrude 110 hp, -89.

 

[lark2004]

Re: termostats

should be on top of heads

 

[seahorse5]

Re: termostats

On your crossflow V4 motor, the thermostats are in a housing located at the lower aft end of the cylinder block. The housing has the 2 water hoses from it to each cylinder head.

 

[lark2004]

Re: termostats

oops, my bad, sorry bout that

 

[asok]

Re: termostats

Is it the house that is attached with ~10 bults?

 

[OBJ]

Re: termostats

asok....look below the exhaust cover at the rear of the engine. You will see a roughly rectangular cover with sloping sides. Held to the engine with three bolts. The t-stats will be under the cover.

 

[asok]

Re: termostats

Can it be removed when engine still in water?

 

[Johnson110]

Re: termostats

i have that same engine, i would do it out of the water, you have to loosen the lower cowling to get at the bolts, they are hard to get to so take your time with this, a bit of advice take the assembly out, assembly before you put back on to engine, use yellow 3 m glue to assembly thermostat to housing then withsome fine wire wrap it around the housing before you put it back on to engine, also get new bolts with smaller heads to wrench it back up, its a pain but it can be done. good luck!

 

[OBJ]

Re: termostats

I have an 86' 90hp which is basically the same engine also. Like johnson said, take it outta the water. I have changed the t-stats without dropping the pan but it's much easier if you do. Be gentle with the bolts as the tend to gauld and can be hard to remove.

 

[asok]

Re: termostats

I can't get it out of water now, and I'd rather fix this as soon as possible. But it is possible to do this in water, but harder? <br /><br />I just want to check that they are ok, cause I have a possible overheat problem.<br /><br />Is there anything I can do to check the cooling canals while still in water?

 

[Solittle]

Re: termostats

You can check the cooling system using temperature sticks available from your marine parts supplier.<br /><br />Yes I suppose it is possible to do this in the water if you can stand on the bottom behind the motor. I would not attempt it. This is a pain in the butt job in the best of conditions. Many professional wrenches will want to pull the powerhead to do this. I did this job earlier this year on one of my 1987 110 hp and am a driveway wrench.

 

[rodbolt]

Re: termostats

if it is a flat back crossflow its doable. if this is the bubble back It would be possible in the water but difficult. most bubble backs take me 1 to 1.5 hours if the bolts come out.<br /> good luck and keep posting

 

[asok]

Re: termostats

Ok, I'll go down and see if I should give it a try then... <br /><br />Annother question: Is it the same sensors that opens the termostats as gives raise to the overheat alarm? Is there any way to check that they are ok? (The sensors that is)<br /><br />Thanks for all your help!

 

[Solittle]

Re: termostats

The lower bolts are the problem. I used a 1/4" socket wrench with an extra long extension (maybe 12") and a universal plus an open end/box 7/16" combo. Mine are the bubble backs.<br /><br />Like johnson 110 I preassembled mine prior to installation and held it together with rubber bands until I got the bolts started.

 

[marinemech]

Re: termostats

to test warning horn: key on ground the brown wire coming out of the cylinder head horn should sound also if you get at the thermostats be careful when reinstalling most of those engines had them installed backward at the factory have your dealer show you the correct assemble before reassembly <br /><br />good luck

 

[asok]

Re: termostats

I have tested the warninghorn and it works just fine. What I'm wondering is if the heat sensors really are working correctly. How do a sensor behave when it's not working properly?<br /><br />It seems to me as checking the termostats is too hard while still in water, so I better check everything else first. <br /><br />Anyway, my problem is that the overheat alarm goes of after going full speed for 5-10 minutes. So the question is wether it really is overheated, and if so, why? There is a good throughput of water in the cooling system so the impeller is working..

 

[Solittle]

Re: termostats

asok - If you have an overheating motor best to find out why as you can trash a powerhead quickly. I would replace the waterpump and thermostats no matter what else you do. You WILL cook your motor if these are not working properly as they control the flow of cooling water through the motor. <br /><br />Other places to look are the deflectors in the water jacket under the head and crud in the water jackets.<br /><br />You can confirm that the motor is in fact overheating with temperature sticks available from your dealer.<br /><br />I have a pair of 1987 OMC 110s & did all the above within the past year.

 

[marinemech]

Re: termostats

moters warning horn sounds after 5-10 minutes check water pump pay particular attention to the seal area which is inside pump housing remove the cup. they usually wear egged shaped allowing exhaust gas to enter cooling water.best bet is to install a new water pump kit which has been upgraded to help eliminate this problem

 

[asok]

Re: termostats

I better get the boat up on land then...<br /><br />Correct me if I'm wrong now. <br /><br />The impeller is a part of the waterpump that makes cooling water go through the engine. The termostats open cooling-canals to the cylinder-tops on certain temperatures. <br /><br />I can see that when running on full speed, there is a lot of water going through the engine (by looking at the outgoing water hole). Doesn't this mean that the waterpump is working properly?<br /><br />If that is the case, then what is left is the termostats or the heatsensor. Am I right?

 

[reeldutch]

Re: termostats

you should also check the midle waterflow restrictors behind the cylinderhead.<br />if they are never replaced after 15 years of service they swell up and block the wrong passages and will run your bottem 2 cylinders hot and you might never know it.<br /><br />reeldutch