Somebody Explain this to me Re: T-Stats Question

[boscoe99]

I would guess that with sufficient water flow all of the air should be completely purged from the system.

Now as to why crud accumulates where it does, I can only hazard a guess. Maybe each time the engine stops, some water gets trapped in the horizontal bore of the thermostat cavity. As that water evaporates it leaves garbage behind. If my theory is correct then a high time engine with low cycles (starts and stops) would be much less prone to crud build up than would be a high cycle engine. We often take engine calendar life and engine operating hours into consideration but don't make much mention of any effects that starts and stops have.

[99yam40]

if there is just enough water flow to reach the exit port, should there still be an air pocket up above it?
I am just trying to find a reason for the salt to remain up at the stat on one side

[boscoe99]

that was on a F150 and was not tilted up as the F250 was during his flushing.
in his next video I did not see anything coming out of the stat housing, strange.

I still wonder with motor tilted up causing stat area to be the highest point, where does the air go?
has to go downward to get out.
with a small amount of water flow will it be enough pressure to force the air down and out?

Air should go down and out the same passageway that water will soon follow thereafter. Assuming of course there is sufficient water pressure to raise the level of the water to the level of the thermostat exit port.

[pstephens46]

that was on a F150 and was not tilted up as the F250 was during his flushing.
in his next video I did not see anything coming out of the stat housing, strange.

I still wonder with motor tilted up causing stat area to be the highest point, where does the air go?
has to go downward to get out.
with a small amount of water flow will it be enough pressure to force the air down and out?

May need a little more clarification. Yes an F150. For some strange reason, when attached to muffs AND flush hose at same time and NOT running, no peeing or water from bore. Start the motor and water pours from both.

The obvious point is running the motor will push a hell of lot more water than the flush port.

[99yam40]

that was on a F150 and was not tilted up as the F250 was during his flushing.
in his next video I did not see anything coming out of the stat housing, strange.

I still wonder with motor tilted up causing stat area to be the highest point, where does the air go?
has to go downward to get out.
with a small amount of water flow will it be enough pressure to force the air down and out?

[fairdeal]

Where's the video?

http://www.yamahaoutboardparts.com/f...-bore-f150txrd

[fairdeal]

it may just never get any water up there.
just a pocket of air that has no where to go

No, 99 is mistaken imagining an air pocket.

The Yamaha thermostat is constructed with small bleeder vents to allow air to pass, even when the thermostat is shut tight cold.

Look at pstephens video posted today, you will clearly see the flush water jetting out of those bleeders.

[HMBJack]

it may never fill completely.

with that stat area being the highest point, it may just never get any water up there.

just a pocket of air that has no where to go

>>> Yes exactly! This supports the idea of drilling a small hole or two in the face of the T-Stat to allow air and some water to pass. Two small holes in the T-Stat probably won't affect engine operating temperature. At 160 degrees and above, the T-Stat will be wide open anyway. It's at IDLE that we're trying to accomplish flow rate to rise salt out. I never thought of an air pocket developing but that makes perfect sense. It's at the highest point of the engine. Kinda like the last scene of the Perfect Storm when the boat was upside down.

If air could be expelled, at least SOME freshwater would make it up to the highest T-stat bore (with muffs on and engine running). Thoughts?

[boscoe99]

The flush hose on the motor.

[pstephens46]

Maybe measure the ID of the flush if you can/want to.

Of the garden hose?

[99yam40]

I have a feeling boscoe hit on the problem.
with the flush hose so small and trying to fill the block with the water dumping out as you fill it, it may never fill completely.
with that stat area being the highest point, it may just never get any water up there.
just a pocket of air that has no where to go

[boscoe99]

Maybe measure the ID of the flush hose on the motor if you can/want to.

[pstephens46]

Do that and let us know please.

Also, use just the garden hose fitting if you don't mind with the engine not running so we can see how much water flows out. Given the small diameter of the garden flush hose I can't see it being a whole lot.

I will. Not sure if tomorrow or Sunday. Fairdeal may beat me to it. Actually wouldn't be bad to see his V-6 and my I-4.

[boscoe99]

I'm stocked up on Alodine and zinc primer. I don't know if any of these flush ideas will work. Most of this residual salt crud should be somewhat diluted by running in the saltwater itself. At least moved around some. I removed my excess with a paper towel. No scraping needed. It still chewed a hole by what I assume to be galvanic corrosion.

I'm thinking of removing the cover and stat just to see how much fresh water will flow out at idle, etc.

Do that and let us know please.

Also, use just the garden hose fitting if you don't mind with the engine not running so we can see how much water flows out. Given the small diameter of the garden flush hose I can't see it being a whole lot.

[pstephens46]

I'm stocked up on Alodine and zinc primer. I don't know if any of these flush ideas will work. Most of this residual salt crud should be somewhat diluted by running in the saltwater itself. At least moved around some. I removed my excess with a paper towel. No scraping needed. It still chewed a hole by what I assume to be galvanic corrosion.

I'm thinking of removing the cover and stat just to see how much fresh water will flow out at idle, etc.