Are water pressure gauges useful or waste of money?

[Alex Head]

My boat is currently in the shop getting an hour meter installed. I have seen some boats with water gauges but I do not know the benefits of these. Are they worth it? What are the benefits?
I have a Tohatsu 50 tdli

Thank you!

[Trimix]

What water pressure are the guages measuring ?

I thought the water was in an open system, so where is the pressure ?

[Alex Head]

Water pressure in the motor somewhere. I actually don't really know. Sold as water pressure gauge, but on dial face just says PRESS.

[jyasaki]

You will have some amount of pressure where the impeller drives water into the power head.

Would a gauge be useful? Depends on whether or not you actually monitor it. (Same is true of the telltale, which is a poor man's water pressure indicator. The few times I've picked up kelp that blocks the water intakes, the motor went into limp-home before I ever looked at the telltale, so I'm not sure it's the greatest primary indicator. I'm fairly sure that my monitoring would have been the same with an analog gauge.

jky

[Pikey Dave]

Originally Posted by Trimix

What water pressure are the guages measuring ?

I thought the water was in an open system, so where is the pressure ?

If there was no pressure, water wouldn't circulate around the system. The pressure will be highest as it leaves the pump & gradually drop as the water moves around the system. It will still have a pressure as it leaves the engine by whichever orifice it chooses. I have N2K water pressure sensors fitted to my engines, these display pressure on my gauges & plotter. The sensors screw into the powerhead & measure pressure in the powerhead waterways. At tickover I get around 5psi, at full chat this goes up to about 20psi. Reassuring to see & not to be guessing by looking at the teltale.

[Trimix]

So really the best solution would be a simple alarm - say a light, that comes on if the tell tale stops flowing water. No need then for pressure gauges, just a simple fow device that operates a circuit - remotely, and a light comes on the dash.

That way you dont need to look at guages, that fluctuate, just check the engine if the big red light comes on.

*patent pending*

[Wibs]

Originally Posted by Trimix

So really the best solution would be a simple alarm - say a light, that comes on if the tell tale stops flowing water. No need then for pressure gauges, just a simple device

This is the job I give to the wife when she's onboard. If this device could be invented, then there would be no reason for the wife.....!


Hummmmmm

[Pikey Dave]

Originally Posted by Trimix

So really the best solution would be a simple alarm - say a light, that comes on if the tell tale stops flowing water. No need then for pressure gauges, just a simple fow device that operates a circuit - remotely, and a light comes on the dash.

That way you dont need to look at guages, that fluctuate, just check the engine if the big red light comes on.

*patent pending*

But that's too late, you don't get the alarm until the system fails. With a pressure gauge you can monitor the condition of the system & anticipate a failure before it happens. If the impellor is on its way out, you will see the water pressure gradually start to fall off over successive trips out. By having the gauges, I know the characteristics of the boat & know what I should be seeing. What you're proposing already exists, it's called an over temp alarm Which I think has already been patented

[uncle al]

Water pressure gauge fit one YES, it could save you a p/h, when running no water pressure stop obm asap if not sooner.

[Alex Head]

So it sounds like it is a way to make sure your engine cooling system is not clogged with debris. But who knows if it is worth the extra expense of the gauge and installation.

[Alex Head]

Originally Posted by Pikey Dave

But that's too late, you don't get the alarm until the system fails. With a pressure gauge you can monitor the condition of the system & anticipate a failure before it happens. If the impellor is on its way out, you will see the water pressure gradually start to fall off over successive trips out. By having the gauges, I know the characteristics of the boat & know what I should be seeing. What you're proposing already exists, it's called an over temp alarm Which I think has already been patented

Good point. So it is a worthwhile investment? (Strange that you can choose so many gauge options on a boat, but not on a car.)

Considering that the motor is typically half the cost of the boat I would say the more you know about it, and that it is working properly, the better.

[Trimix]

Actually I think my Suzuki engines have a temp warning light, so I can just rely on that. I wonder when it comes on ? Boiling, hot or just warm.

[Pikey Dave]

Originally Posted by Trimix

.........I wonder when it comes on.........

Too late probably

[Trimix]

Ha, yes, probably.

Ive got the Suzuki tech chap comming to visit me in the week to do a printout on my engines and hand me some log books which got forgotton when I got the boat, so I will ask him.

Hes making a special trip, which is nice of him.

[nugent]

Allwaŷs fit one my self,


Find it invaluable, as aforementioned you see the pressure dropping daily,
you know about. Forth coming doom, long before any alarms have spoiled your planned day out,!

[Nos4r2]

If my Opti didn't have one, I wouldn't have known that the guy who'd serviced it before I got it had messed up fitting the new Poppet valve parts.

[Festinghouse]

its probably worth noting that a worn out impeller would show low pressure, but a blocked tell tale outlet would show high pressure - both meaning water not circulating around the engine properly

[Nos4r2]

Originally Posted by Festinghouse

a blocked tell tale outlet would show high pressure - both meaning water not circulating around the engine properly

Unlikely. The telltale is a tiny proportion of the water flowing through the motor.99% of it comes out the prop centre.

[jyasaki]

What NOS said. The telltale is just that - a water circulation indicator; it's not required as a water ejection route.

jky

[Trimix]

So, wouldnt it just be simpler to measure engine temp then ?