1980 115 hp - Themostats

[JimJamie]

I just replaced the impeller. Now I have water flowing out of both upper ports, even at idle, and after the engine has been idling for 10 minutes.
The heads are not getting hot either.
I'm leaning toward a thermostat kit from Sierra.
Could it be anything else?

Before the new impeller the water flowed out of the left upper port only at idle. The old plastic impeller housing was "corroded". (that is the best word I can find to describe what it looked like.)

[phillnjack]

you are dead right to think thermostats.
make sure you get the full kit and gaskets etc.
there should be just a misting on idle and then a decent amount when revved up etc as the byp*** opens.
This is a bad situation as a engine running too cold wears out the rings faster than a slightly over heated engine.

the only reason you had water coming from one of the ports before was not enough water flow and the thermostats now opened up due to better pressure.
If no temp guage the best way is to put hand on head when its warm and hope to keep it on there for a max of 10 seconds but normaly about 5 to 8 secs.


phill

[JimJamie]

Yea, good to know as I knew underheated heads was not good, but did not know the eventual result.

A friend of mine said 5 sec of contact before I can't take it will be about 140 degrees.
That should be close enough.

What does byp*** mean? I'm thinking "byp***", or was that a browser glitch that messed up the word? (oh I get it, the forum deletes naughty words, ha ha)

I've been told the thermostats are hard to get at when replacing. I know where they are by looking at the back of the engine.

Yes, the Sierra kit comes with a bunch of gaskets.

[Elton Smith]

Byp*** is when the thermostat is closed and it just comes out the telltail. Water can't get in the water jacket till the thermostat opens.On some models you have what they call an overboard indicator.That is a rubber hose under the motor that will drip water to let you know the thermostat has opened.

[phillnjack]

what engine has this overboard indicator ?
ive only seen about 10,000 outboards and ive never seen one with that on for sure.
rubber hose that drips water to tell you thermostat is open ?
who told you this ?
mercs don't have them johnnyrudes don't have them tohatsue don't have them yamagha don't and neither do Suzuki or Volvo penta.
so what does ?
to know the thermostats are open you look at back of engione and see the two top exhaust relif holes, when you see water coming from there the thermostat is open.
sometimes this is just a fine mist, but on full throttle it will pour out.
if you get continuos water from these ports the thermostat is stuck open.


phill

[JimJamie]

The cork rings

I took off the thermostat ***embly. Tough to get at it and I did need heat on the center bolt, and I cut off one of the tubes. (don't do that they're $12.00 each)

One thermostat was stuck open after I tested it in hot water.

The thermostat kit arrived today.
I don't recognize the cork rings, but I think they go on top of the thermostat. Is this correct?
Any tips on ***embling and installing the kit?
Should I use gasket sealer on both sides of the gaskets?

[phillnjack]

the stuck open thermostat is definitely the worse one. but the other one probably opens as well under a bit of pressure, that would cause the water from the exhaust outlets at the top.
the little gaskets for the thermostats go on after the thermostats.
the best thing to do is to put all the bits back together with the middle large gasket glued in place.
getting it all back on is 10 times harder due to the springs !!!!!

here is a link that shows the thermostat and all the parts


Johnson outboard thermostats and kits

phill

[JimJamie]

OK, next issue. I'm in northeast Ma-chusetts. It is cold now. My intention is to use gasket sealer as I put it all back together. Will the cold effect the curing enough so that I should wait until Spring to do this? As the weeks roll on the urgency wanes.