Thermostat?? no water

[grantrs]

82 25hp evinrude.<br /><br />Just finished doing some work on it for last few weeks. mainly gbox.<br /><br />Put it back together, put the hose on it and started, waiting for water (telltale) no water , still no water.<br />It crapped itself with a bit of smoke then was rough so i basically shut it down asap.<br /><br />Pulled the lower unit and the stupid rubber thing that connect to the copper water pipe was in a ball so stopping water flow.<br /><br />Motor was fairly hot to touch<br /><br />2nd go:<br /><br />i put the hose straight onto the water pipe no lower unit on, started it, bit of a spray but wasn't fast enough for me so shut it off.<br /><br />3rd go :<br /><br />Change rubber bit, glued it in, put lower unit on again, made sure impeller was on shaft, all ok its a fairly new water pump kit. plugged in water started, still no water out spray hole, and motor seems to be running ok after the first atempt.<br /><br /><br />What could have happened during the first run? anything bad?<br /><br />where do i find the thermostat in this thing? wouldnt hurt to replace it?<br /><br />any other ideas, from looking at the water pump it all looks to be working.<br /><br />all i can think of is the thermostat is stuck after sitting for a while

 

[rodbolt]

Re: Thermostat?? no water

Tstat has nothing to do with tell tale on that motor. sounds like possibly the tube or restrictor or fitting on the block is plugged. that or the pump fried, as far as damage it could have popped a head gasket, that motor runs siamese cylinders and is notorious for popping head gaskets and warping heads if it overheats. but replacing t-stats should be a preventative maint action never a corrective one.<br />by the time you NEED a pump or a tstat the odds have grown that you will also NEED a head gasket or piston.

 

[KYHunter2]

Re: Thermostat?? no water

Well, depending , how long you ran it without coolant. You could have scorched the cylinder walls, alot of different results from overheating. How hot was it? I am not familiar with your motor. <br /> You really need to get a manual for your motor. If you are going to maintain it yourself. <br /> Are you positive you have the impellar in exactly as the old one was. <br /> <br /> Meaning impellar fins turned the same way in housing ? <br /> <br /> If you've never serviced the "T" stats , YES, real good idea to do them. I do them when I do water pump. Cheap insurance. <br /> <br /> If you only ran for a short period , you may not have done any serious damage. <br /> I'd have to say , Id quit running it until I knew for sure ,the cooling system was functioning correctly. <br /> <br /> If your motor has a temp alarm , did it sound? If not , Why not?<br /> <br /> Im sure one of the experts will come along to help.<br /> Good Luck,<br /> KYHunter

 

[grantrs]

Re: Thermostat?? no water

Well from what i understood with this motor, that no water comes out the exhaust relief until the tstat is open. Therefore it has everything to do with the telltale spray. ?<br /><br />KYhunter, believe me im having trouble finding a manual to suit it. Wasnt run for that long, afterwards it started first pull and ran as normal so i dont think its broken (yet), no smoke clouds etc<br /><br />I had replaced the water pump earlier and have been using the boat for a while, pump is going fine. Not much to them really.<br /><br />OK there is a piece of rubber missing from that thing that was squashed so im guessing it has gone and gotten stuck in the tstat? next problem where do i look for it? i can try and get some photos of the motor if thats any use??<br /><br />Basically what i did with the hose was applied water pressure to the tube the same way the water pump would if not a bit more, there was a lot less water spraying then there should be. <br />That is why im thinking the thermostat might have this rubber bit jamming it. Does this sound like the problem?

 

[ezeke]

Re: Thermostat?? no water

That could be. Take the thermostat out and run compressed air back through the opening there with the lower unit off, should blow the obstruction out if its the rubber part. It would probably be stuck near the top of the water tube.<br /><br />If you haven't worked on the thermostat before, you need to take off the outer cylinder cover (water cover). You will probably want a new thermostat 378065 and water cover gasket 327674.<br /><br />See the BRP parts diagram for your motor here: BRP Parts Diagrams <br /><br />Go to your model, then look at the "Cylinder and Crankcase" diagram. The third icon in the group of four will enlarge the diagram so that you can read it or you can print it.

 

[Texasmark]

Re: Thermostat?? no water

I bought a '72 70 hp in mid 80's. Ultimately it froze up at WOT of all places, and I had to do a complete block overhaul.<br /><br />If you are there and there is any question about the tstat, take it out and check it or just put in a new one.....best idea as they are cheap.....got one for my current Merc for about $12 (the kit including gaskets). Not worth taking a chance.<br /><br />For testing I just put in in a pot of water on the stove and watch for the end to slowly protrude..should start about 120 degrees (for Merc). A meat or candy thermometer will give you an idea as to where you are. If the water boils and no open, she's stuck.<br /><br />Mark

 

[grantrs]

Re: Thermostat?? no water

Thanks guys, there is actually a diagram for my motor!!!! <br /><br />I just started pulling it to bits last night looks liek i was going for the right spot.<br /><br />Cheers will see what i find.

 

[grantrs]

Re: Thermostat?? no water

I've pulled the water cover off, tstat looks half stuffed, and clogged.<br /><br />Will put a new kit in it tomorow.<br /><br />Cleaned out all the salt and crap, flushed in there with the hose, but no rubber bit. may have lost it on ground, or somewhere else.<br /><br />What is the best thing to dissolve the salt buildup? <br /><br />Now having flushed the galleries out, there sould be nowhere else that would cause a blockage?<br />i flushed from the water pipe up and from the tstat hole back out the water pipe.

 

[OBJ]

Re: Thermostat?? no water

Try some Salt-Away for cleaning the innards of the block. Follow the instructions on the container.<br /><br />Depending on how large the piece was, it may be gone already. No real way to tell other than tearing the engine apart....well maybe the head.<br /><br />I'd put it back together and run it and monitor the engine temp. If your are running on muffs, you won't see a lot from the exhaust relief ports. No back pressure on the engine (out of the water) so most every things just goes out the exhaust.

 

[ezeke]

Re: Thermostat?? no water

Is it really salt from salt water? If it is salt, get a product called Salt-Away.

 

[grantrs]

Re: Thermostat?? no water

After some more dramas with snapping a hydrofoil off it is now all back together, new thermostat and water gasket on.<br /><br />But now i think its going to be the head gasket stuffed after the first thing happened when the thermostat stuck.<br /><br />I started it up, with flusher on, not much water again but lots more smoke then normal, pretty sure it was white ;(<br />Sounds like head gasket now??<br /><br />I mainly work on cars and i know a head gasket can be a pain, whats the deal with these things?? is it going to be basically like the water cover but the next layer? <br />Is it simply a case of taking head off, fitting new gasket and goo and doing back up?<br />i dont think it would have got hot enough to warp.<br />Do they have a tightening pattern or torque setting?<br /><br />thanks for the help.

 

[grantrs]

Re: Thermostat?? no water

hmm also just thinking, it started to put out a bit of steam when under way, so that would also indicate head gasket and its now gotten worse?

 

[fireman57]

Re: Thermostat?? no water

The head comes off pretty easy. Check wil a flat bar to make sure there was no warpage and take a peek at the cylinders for scarring and/or metal parts. Do a search for head bolt torquing and you should get the tightening pattern and totque numbers. Red search feature at the top of the page.

 

[OBJ]

Re: Thermostat?? no water

Another possibility is the exhaust cover jacket gasket leaking and blowing water into the cylinders. Hard to say which.<br /><br />Basically, remove the 10 head bolts and bull the head off. If the head gasket is blown, it should be apparent. <br /><br />Depengine on the gasket you get, some will require a LIGHT coat of gasket sealing compound and some do not. It will be printed on the gasket.<br /><br />Of course make sure the surfaces are clean.<br /><br />Start with the middle head bolts and work out in a spriral pattern. Torque is 18 to 20 ft lb. Apply the torque in at least two stages.<br /><br />Another thing, if your are getting water into one of the cylinders, once the head is off, you should see places that are "washed" on the top of the piston.

 

[grantrs]

Re: Thermostat?? no water

thanks guys, the exhaust cover being the big square thing on the side? <br />if so i think i saw it in the manual i have, there is a small hose connector on that which drains to outside of the engine surround.<br /><br />this had water blasting out when i put the hose on the water pipe, is that normal?

 

[grantrs]

Re: Thermostat?? no water

Can anyone tell me what that hose is for and should there be water coming out of it?<br /><br />I've look all through the manual i've got here and says nothing about it or even labels it.<br /><br />is a compression check going to test if the head gasket is gone?

 

[OBJ]

Re: Thermostat?? no water

The parts book calls it the "overboard indicator". We just call it the tell tale or pee stream. The hose should lead over to the starboard side of the pan and connect into a nipple thru the pan.<br /><br />When the engine is running, you should have a tell tale stream of water here. This indicates that the water pump is working. After a while, you can usually tell what condition the impeller is in by how hard the stream is peeing.<br /><br />The compression test can indicate a bad head gasket, yes and sometimes no. Depends on just how bad the gasket is.

 

[grantrs]

Re: Thermostat?? no water

Ohhh ok thanks for that. After previous discussions i was under the impression that this motor had no tell tale stream but only a mist spray from the exhaust port.<br /><br />I've only seen a few drips come from that nipple nothing more. i have since cleaned the hose out, so posibly it was jammed.<br /><br />Ok, in this case where im thinking the gasket is cooked, around the exhaust cover or under it if this water that should be going to the tell tale is leaking what gasket should i be checking?<br /><br />Thanks a lot for the info, much appreciated

 

[grantrs]

Re: Thermostat?? no water

Ok guys, i pulled the exhaust cover off, and the head.<br />Not sure whats going on, head looks like its being steam cleaned. (plugs are brand new, not steamed).<br />See photos attached<br /><br />In the bottom cylinder, the very bottom intake port? there is water coming in from it when moving pistons with flywheel.<br />Im assuming thats the intake cover on that side? under the fuel pump, by the looks the gasket might be original as the gasket is engine paint colour. ie been sprayed over.<br /><br />So what is likly to be the problem on the intake side? do i target it next and take the cover off for a look?<br /><br />Pictures...<br /><br /><a href="http://usera.imagecave.com/grant584/DSCF0286Large.JPG">

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[grantrs]

Re: Thermostat?? no water

Is that the exhaust bypass side too? in the bottom photo the port at the bottom on the right near the water is where its being drawn in by the piston.