Telltale Water Wizzer Wonders

[oldmako69]

Tossed into the abyss of the interwebs for your consideration -

Two identical engines (2005 F225TURDs).
One well pump.
One Y connector screwed onto the well pump hose.
One of the Y connectors ends to each engine.
Full PSI on well pump.

Both engines have water flowing out of all the exhaust passages and water intake on the lower unit.

Only one engine has a stream out of the telltale hole. IF I partially close the SOV on the engine with good flow, the other one will eventually begin to stream as well. The tell tale flow under normal operation of the engine is fine, although not a strong as the other engines.

The engines have about 280 hours total. Both engines thermostats (and anodes) were replaced this spring. Both of the old ones came out with a surprising amount of salt crystals embedded in and around them. So much for the previous owners "Oh I always flushed them!"

Is low flow out of ones pee-hole cause for concern?
Were the embedded salt crystals a cause for concern?
Is 'vat-flushing' the engines (individually) with a salt ridding solution a worthwhile endeavor or just a big moist waste of time?
Why is the Chesapeake Bay devoid of fish?

[99yam40]

yes,yes,yes, & over fishing wiped them out

water pumps & PRVs would be a good idea also.

have you checked to see if the exhaust stack corrosion has been repaired on those motors?

[DennisG01]

When you say "full pressure", what is the PSI at the engines? And, probably more important, what is the flow rate (GPM) coming out of the hose at each engine? It might just be that there isn't enough flow, coupled with variables such as impeller health and water taking the path of least resistance.

[oldmako69]

99yam40,

The water pumps were replaced late last fall and don't have but about 50 hours on them.

The PRV's - pressure relief valves? I have no idea about them or their condition.

The engines have not had any exhaust work done. They only have 185 hours on them.


DennisG01,

I have no idea what the pressure is. Its a well system and the pressure is what I would call "low". That is based on my using the same hose with a nozzle during wash down. Its much less (psi and volume) than one would expect from a typical residential / city water garden hose.

This is why I think that flushing both engines at once might not be the best idea, and that's also why one engine is reluctant to pee under this set up.

[99yam40]

does not hurt to check on the PRVs, and water pump impellers can come apart anytime


any time you have a problem you adjust.
flushing one at a time might be a good idea

[rodbolt17]

hahahahaaha
dumbest thing on the net lately.
flush two motors on the same 3/4 hose.
really????

[DennisG01]

This is why I think that flushing both engines at once might not be the best idea, and that's also why one engine is reluctant to pee under this set up.

Yup, I agree. One hose only. Plus, if you do that and you see that the offending pee'r is now doing it proper, you've solved the "mystery". But, yeah, it totally makes sense that you're having that issue with the running on two hoses. FYI, hoses (even city water) never supply as much water as when the gearcase is sitting in water.

[TownsendsFJR1300]

You need one hose at a time to EACH ENGINE.

Re salt and flushing. I flush religiously, brackish/salt water use.

When I replaced the thermostat, etc, I found some salt build up I did
NOT expect to see...

Think about it (for salt water use). You run you engine to your fishing spot/beach, etc, turn it off. The engine is nice and hot as the salt water
drains... Salt cooks and some of it adheres inside the block...

Repeat MANY times for the day, then for the year(s). Salt accumulates, period

Flush all you want. but you likely know how hard that salt is to remove
by hand with a scraper, etc...

Its the same reason engines that have cooling issues, go into safe mode after a certain RPM.

Where's all the salt build up? In the head and lower cylinder water passages, where it's the hottest and the salt builds up the most.


BTW, after replacing a balancer and testing, (engine off), I put the hose AND NOZZLE on the engine flush hose fitting. I could not get it to come out the tell tale. Remove the nozzle, tell tale flows.
(That's with about 65 PSI, thru 3/4 line-plenty of water)


.

[boscoe99]

hahahahaaha
dumbest thing on the net lately.
flush two motors on the same 3/4 hose.
really????

Yes, but there was 30 psi of water pressure. At the tap. Hose was only 100 feet long.

[fairdeal]

dumbest thing on the net lately.
flush two motors on the same 3/4 hose.

ok
but the Yamaha flush port hose - which on the F225 circles the engine - is, what, 8 mm?

that's a cross-sectional area of 50 sq mm

(the "garden hose connector" fitting itself has an ID of 6 mm -
that's a restriction to a x-section area of only 28 sq mm)

a 3/4" hose has a cross-sectional area of 284 sq mm - more than 5X larger than the hose its feeding

why wouldn't that be enough for 2?

sure, as Boscoe observes, the length of the supply hose is "a factor" - but....


I have always wished I understood hydrodynamics - but I don't.
too lazy to put in the effort necessary

[oldmako69]

Interesting replies.

I fully realize that flushing two at once is less than ideal, hence my comment highlighted above by Dennis. But won't the length of time have an impact as well? The pressure of the fresh water doesn't dissolve salt crystals, the presence of it does.

I have two hoses at my dock. One gets hooked up to the engines while I wash the boat. I'm old and slow. Hence the water is flushing through the engines for a LONG time, even though its at reduced PSI. The long time interval ought to allow the water to put as much salt into solution as possible because of the volume of water which passes through the cooling system.

I see a lot of watermen tooling around with old Yamaha's. I wonder how often they flush their engines? My guess is never.

In addition to flushing, I'm going to buy a big tub and immerse & run the engines a few times per season using a solvent solution of some sort.

[boscoe99]

....


I have always wished I understood hydrodynamics - but I don't.
too lazy to put in the effort necessary

What about aerodynamics and thermodynamics?

Does the low water pressure at the end of a 100 foot hose suck the water from the tap and to the end of the hose?

Does low voltage suck the electrons from the high voltage side of a circuit?

Like the low air pressure within a cylinder that sucks in the air from outside the motor? An esteemed author of aviation matters says that this is what happens in a piston engine. When the airplane flies into outer space why does the motor stop sucking?

Heat kills or so I am told. How come a pool of 70 degree water, holding much more heat than air at 120 degrees, will kill someone by dropping their temperature (degrees) too much (hypothermia)?

We refer to the heat (BTU's) index and then express it in the form of degrees.

I wish also that I had paid more attention is school. And read more.

I am so confused. The more I know the less I understand. All the things I thought I figured out, I have to learn again.

[TownsendsFJR1300]

Some interesting reads re chemical flushing as water ALONE won't do it:

http://www.yamahaoutboardparts.com/f...g-th19434.html

Post 21 specifically:
http://www.yamahaoutboardparts.com/f...h27868-p2.html




.

[pstephens46]

hahahahaaha
dumbest thing on the net lately.
flush two motors on the same 3/4 hose.
really????

Rodbolt would agree at some point this was a complete
dckhead thing to write.

[99yam40]

Heck I never even owned a 3/4" hose.
5/8" and 1/2" is all I ever needed