Cleaning Thermostat Housing

[Jason2tpa]

Well that's great to know. I was told (I called Salt Away headquarters) and they said to not flush it once it was applied. This way it keeps working...

If I remember correctly, Salt X stated to do the opposite. Flush with fresh water thoroughly, assuming because of how strong the chemicals are. I don't know, I just followed the directions. And yes, it did leave a whitish water stain on motor.

[Jason2tpa]

My boat is stored on a lift so I cannot flush with muffs. I also am reluctant to running my engine with ONLY the garden hose flush fitting at the base of the powerhead because: (1) My Owner's Manual says not to do it, and (2) I think I will prematurely wear my water pump impellor. Agreed?

Those on this thread were all pretty stunned when rodbolt made this enlightened statement:

over the years Yamaha said you could then could not.
for extended runs like decarbing I use both.
for simple runs like testing or warming it up for a test I use the flush port.
never had an issue just keep the RPM below about 1000.
been doing it that way since the latter part of the 90's.

If a yam professional mechanic says it's ok, I'm good with that. Your engine so it's your call.

[TownsendsFJR1300]

I've used Salt X with my previous engine. Its the same purpose product as Salt Away. With that engine the stat housing was vertical. I'd dilute the Salt X down, have the stat open to air and pour the solution down her throat while running engine on muffs. Then a thorough fresh water flush for 10-15min after. Stuff worked great.

Well that's great to know. I was told (I called Salt Away headquarters) and they said to not flush it once it was applied. This way it keeps working...

It does leave the exterior of the engine with hard water spots unless you hand dry it.

Just to clarify, once the boat hits the lift (from an outing), the garden hose hits the factory flush fitting for 10-15 minutes (not running). Then I hook up the SA and run (fresh water only) another 10 or so. Then turn on the SA until I see the soapy solution come out...


And HMB, that looks GREAT!!

Did you clean that with a chemical, water, sanding, or combination of?

I gather with a swim platform (assuming you have one) you still can't reach the LU(s) to slip muffs on?
Have you considered installing "walk about extensions" to the rear lift cross member?

[HMBJack]

I am the Original Poster and here is what my T-Stat housings (all 4) look like now after I cleaned and coated them with a coat of oil based paint:





As stated earlier, my Starboard T-Stats on each engine had 50% MORE salt crystals than the ones on the port side of the powerhead.

My boat is stored on a lift so I cannot flush with muffs. I also am reluctant to running my engine with ONLY the garden hose flush fitting at the base of the powerhead because: (1) My Owner's Manual says not to do it, and (2) I think I will prematurely wear my water pump impellor. Agreed?

Lastly, because my starboard side T-Stats were so mucked up, one thing I can do is to flush with my engines UP and slanted over to favor the Starboard side of the powerhead (i.e. helm turned all the way to the right when engines are in the raised position). If I do this, perhaps my T-Stats will stay cleaner but I still plan to inspect and clean them EACH year.

Thanks and if you have a suggestion for me and my flushing, I'm all ears...

[Jason2tpa]

Besides flushing on muffs with engine to temp, I started using "Salt Away" which attaches between your muffs and garden hose.

Even with the slightly more limited water flow, the unit has a knob atop it so you can turn it on (add the product) without stopping the engine (thermostat is still open, engine to temp-distributed FULLY).

It may take a minute tops, but you can see what appears to be soapy water exiting the engine. Your done...

With all the corrosion / salt water issues I've seen / read here, I consider it a small investment to help avoid the corrosion issues..

Brackish/ salt water use...


IMO, even if only able to flush while in the water / tilted on the attachment, a half minute of Salt Away, certainly can't hurt...

I've used Salt X with my previous engine. Its the same purpose product as Salt Away. With that engine the stat housing was vertical. I'd dilute the Salt X down, have the stat open to air and pour the solution down her throat while running engine on muffs. Then a thorough fresh water flush for 10-15min after. Stuff worked great.

[fairdeal]

Just in case anyone is interested:
The difference between green and yellow zinc chromate paint is that the yellow does not contain uv blocking pigment, the green does (usualy called "lamp black").

I am interested!

Before using it, read somewhere that the paints' Achilles Heel was UV, and hence required a top coat of a different product.

Wasn't worried, knowing that I was only going to use it where the sun don't shine.

but seems like the green is fine anyway.

[TownsendsFJR1300]

Besides flushing on muffs with engine to temp, I started using "Salt Away" which attaches between your muffs and garden hose.

Even with the slightly more limited water flow, the unit has a knob atop it so you can turn it on (add the product) without stopping the engine (thermostat is still open, engine to temp-distributed FULLY).

It may take a minute tops, but you can see what appears to be soapy water exiting the engine. Your done...

With all the corrosion / salt water issues I've seen / read here, I consider it a small investment to help avoid the corrosion issues..

Brackish/ salt water use...


IMO, even if only able to flush while in the water / tilted on the attachment, a half minute of Salt Away, certainly can't hurt...

[cpostis]

Just in case anyone is interested:
The difference between green and yellow zinc chromate paint is that the yellow does not contain uv blocking pigment, the green does (usualy called "lamp black").

[rodbolt17]

over the years Yamaha said you could then could not.
for extended runs like decarbing I use both.
for simple runs like testing or warming it up for a test I use the flush port.
never had an issue just keep the RPM below about 1000.
been doing it that way since the latter part of the 90's.

[dark_star]

I would just like to confirm you are actually running the engine while
using the flush port rather than muffs ??
this goes against what I have been told in the past.

[rodbolt17]

idle speed at about 10 min or so.
make sure you see water exiting the water intake screens BEFORE starting the motor,
use full water pressure.

[pstephens46]

May need to test this.....Pull boat at lift and put on trailer. 10 min drive back to house. Flush with flush port as soon as the boat is in driveway. Is the engine hot enough to keep stat open for a few seconds as the water flows through the port? Might this be enough?

[rodbolt17]

and I never run an F225 on the muffs.
I typically flush using the port with the engine idling.
I do my F150 the same way.
however with the engine off flush water may or may not make it to the top of the cyl head.
almost all Yamaha tell tales stay cold as the water is typically taken from a spot BEFORE it gets a chance to cool anything other than maybe a fuel cooler.

I think the older F and T 9.9/15 used a combination of T stat discharge and cold water.

[pstephens46]

OP said 500 hours time since last time stats were pulled. Based on Fairdeal's, Solo's and this guy's results, I will pull mine twice a year to check for salt and especially "bridging" between stat and wall. My gasket has been re-used several times with no leakage. I had a little salt in the thermostat after about 150 hours.

[panasonic]

Here is what we use on commercial aircraft after corrosion removal to get the aluminum ready for zinc chromate (we use two part epoxy not the spray can stuff) and paint topcoat. Can't see why it would not work on outboards...
AT117 ALUMINUM PREP 8oz KIT

If you use these products remember they are quite strong chemicals and to rinse the areas with plenty of fresh water. Also wear gloves and safety glasses.