Can you run without a tstat check valve?

[Smgbad]

Just opened up the new project I've been getting ready for the water to replace the tstat as a precautionary measure, as both overheat alarms are toast and no longer available.

It's a 1986 Evinrude e150. When I got the tstat covers off, both the thermostat and the check valves are gone, and someone filled the check valve relief hole with a screw and some flex seal. They obvouosly wanted to run with no tstat... Prob because of no temp sensors is my guess.

So I did buy 2 new tstats to install, but wasn't anticipating the check valve being gone and the hole being plugged. Will it be safe to add in the thermostats and not the check valves and leave those sealed screws in the housing pee holes? Or will this not work due to back pressure issues from reintroducing the tstats?

 

[racerone]

Pictures of these screws in the relief holes ?

 

[Smgbad]

Pictures of these screws in the relief holes ?

Not around the boat right now, but the small hole in the tstat housing (bolt on cover plate) has had a small self tapping screw stuffed all the way in there and then the screw head was covered over with flex seal so no water can get out now. Whoever has this before just deleted the whole tstat system including the check valve and the weep holes. I can easily open the hole back up, but without the check valve I don't know if that's a bad idea. I was going to just throw in the two tstats I bought and close it back up, but now that I know there was a check valve and relief hole in the housing, I'm second guessing putting the tstats in.

 

[racerone]

That hole in the cover is a vent hole to allow the diaphragm to move.-----No water should ever leak out of that hole per design.----If water leaks out there is a problem.

 

[Smgbad]

That hole in the cover is a vent hole to allow the diaphragm to move.-----No water should ever leak out of that hole per design.----If water leaks out there is a problem.

The diaphragm on the plastic check valve? I don't see how water wouldn't come out of that open hole of there's no check valve there. There's nothing standing between the flow of water and the hole at that point. I figured that's why the previous owner plugged and sealed the hole. That being said, if I leave it plugged, is it safe to put the tstats back in, or were the check valve a there to prevent some kind of major issue if the tstats fail?

 

[racerone]

Not going to argue with you here.------Hurry and run to a shop and have them explain this system to you.------I am stepping out of this thread.

 

[Smgbad]

I'm not arguing, my man... I'm asking a question. Huge difference.

 

[racerone]

Good luck with the project.---Read post #4 carefully.

 

[Smgbad]

Didn't mean to offend. Just doesn't seem like there's anything there with the check valve removed to stop the water from shooting out like a water pistol. That's what I was asking about.

 

[Smgbad]

Anyone able to tell me what would happen if I just run it with the thermostats and no check/poppet valves? It currently has neither and has been run like that for some time apparently as the bolts hadn't been out in awhile and the gaskets were rotted.

 

[Smgbad]

1986 E150 has no thermostats or check valves installed. Thoughts?

Hi all. Have a 1986 150HP Evinrude that I am trying to do all the preventative maintenance on for the first time. Took the T-Stat cover off and found it has been run for some time with no T-stat and no check valve (goes right underneath it). So the tstat area is basically completely open, and the previous owner shoved a screw in the relief hole in the thermostat housing cover and then flex sealed over it (I'm guessing as they were worried it would leak).

There is a decent amount of gunk I'm seeing in the water jacket, so I'm guessing that's why they were removed. The bolts are sure hard to turn. Got the port side ones out, but they were super hard to turn and are all gunked up... Counting my blessings none of those 4 bolts broke. Considering putting it back as it sits to run without them again...

Should I add the tstat and check valves back into the system at this point, or just leave it be?

 

[Smgbad]

Anyone ever seen the plastic poppet/check valve under the tstat melt?

86' Evinrude E150. Opened up both sides for t-stat maintenance. Found both t-stats missing port side check valve and spring gone, and 1 melted check valve and spring still installed on starboard side. I've decided to just replace both components on both sides, but has anyone ever ran into the white plastic poppet being melted?