Running too cool. 1993 115

[rothfm]

In the fall i did new stats, and diverters. Both heads always regulated at 140 after coming up to temp.

This Spring, Was having issues at cold starts, with starboard side getting too hot before the stat would open. Would go to 180+, all i had to do to bring it down was give it a short REV or two in neutral-it would immediately come down to 140 and remain there. Port was fine at 140deg steady. All would remain ok till next cold start.

So today...I removed the t-stat housing, All looked ok. I know about the Bleed-Hole. So I installed a new Sierra kit. But I also very slightly opened up the single bleed-hole (just a hair), and also notched each poppet as someone here recommended. It was a very small notch in each.

Now Temps are even, but it only comes up to about 100-105 on Muffs with very cold well water (55deg). Just before this, same well water would allow it to come to temp fine.

Are my Stats even opening? My guess is enough cold water is now getting by the Stats via "3" Bleed holes(bleed and 2 v-notches), and that alone is regulating the block temp at 100-105 with the stats closed.

Does this sound like what is happening? Darn. Wish I Didnt notch those poppets.

I run Seafoam regularly in the fuel, and also do periodic OMC Engine Tuner treatments.

BIG QUESTION: Any issues running like this? At speed its going to bypass alot of cold water thru the poppets anyway and bring temps down correct?

Otherwise it runs really well. I have extra parts, Should I go back and leave it original? (orig size bleeder, and not notched poppets). Its a bubble back, but i've gotten pretty good at doing them

 

[Daviet]

Re: Running too cool. 1993 115

I would put it in the water and run it and then check the temp on the heads, running in that cold of water might give you a bad reading.

 

[rothfm]

Re: Running too cool. 1993 115

Thanks Daviet.

Yea, I'm inclined to take it fishing Saturday with my Thermal gun, and watch it closely. I'm pretty good with these engines, If I didnt run any seafoam or Engine Tune regularly, I'd think otherwise and re-do it.

 

[Daviet]

Re: Running too cool. 1993 115

Let us know what you find out.

 

[rothfm]

Re: Running too cool. 1993 115

So, phrased another way....Is running a crossflow at 100-105 temps at idle ok or a no no?

Has new 143deg stats but believe bleed hole and notched relief valves are bypassing too much water.

Thanks

 

[boobie]

Re: Running too cool. 1993 115

As Daviet said, take it out and run it and see what happens.

 

[emdsapmgr]

Re: Running too cool. 1993 115

Cold lake water temps, or cold household water temps will absolutely affect the cyl head temps at idle. I would not worry about it at this point. Keep in mind that the stats work only at idle. Once that engine gets up on plane, (or you rev the throttle high) the pressure relief valves open in the thermostat housing, causing the powerhead to be flooded with extra cooling water. If the engine idles at 143 and you plane the boat out, typically the powerhead temps will go down 20 degrees, or even more in 45 degree lake water. That's normal. The time to check your head temps is on a 90 degree day summer day on a lake.

 

[rothfm]

Re: Running too cool. 1993 115

UPDATE: (thanks for the replys)

Background. Motor running too cool after opening the thermo housing bleed hole and notching the relief valves.

Took it to the water, same result. warmed to 100 only. Like the stats never got hot enough to open.

Replaced the housing with another, all new gaskets, thermo's and relief valves....BINGO, warms up to 145-150 then drops and holds around 122-135 depending on where I'm measuring.

I'm glad as I know this is a much better state for low speeds, and trolling.


PS....I've gotten good at the bubble back thermo job.. Have it down to about 30 minutes (if the housing is prepped and glued together beforehand. IF anyone wants to chat about it, PM me.

 

[boobie]

Re: Running too cool. 1993 115

Good job. Thanks for the feed back.

 

[GCarlover]

Re: Running too cool. 1993 115

In reading these posts, lots of good advice. But mine is a 140 Looper so don't know exactly what you did Rothfm. My thermostats are in the open position(1987 Johnson 140) I ordered new vernathems; they should be closed, right? Also read that hose temp is not accurate. One I could blow through easily and the other not. One lukewarm, the other ice cold on head and cyl. Few yrs ago I got 120 temp in the lake at the top of cyls. Read this on Evinrudenation: If you perform your own engine servicing, be aware that an accurate temperature reading cannot be obtained while running the outboard on a flushing device. It has to be in the water for the pump, relief valves, and thermostats to operate as they were designed.