Water Pressure Gauges

edgutgesell

Petty Officer 2nd Class
Joined
Jul 18, 2004
Messages
144
Since I have just had a water pump failure, I have been looking into installing a water pressure gauge to monitor my 150 Yamaha water pressure. Maybe I have been looking the wrong place but the gauges, such as Teleflex, seem to be driven by direct water pressure from the tell-tale. This seems to indicate that the gauge would be mounted on the engine somewhere and not on the helm instrument panel. Is there a water pressure gauge that operates with an electrical sender so it could be viewed from the helm?? Maybe I have the operation of these gauges wrong!! Thanks again for your inputs!!!
 

carljh

Seaman Apprentice
Joined
Nov 8, 2005
Messages
44
Re: Water Pressure Gauges

I fitted a Teleflex gauge to my 115HP. The gauge is in the dash and is driven by a pipe from a hole on the top of the cylinder block. Quite simple to fit just remove the existing bolt from the engine fit the Yamaha adapter (not supplied with the gauge), fit a suitable part that somes with the gauge, cut a hole in the dash, fit gauge in hole then run pipe from engine to gauge.
 

gejandsons

Petty Officer 2nd Class
Joined
Sep 11, 2003
Messages
134
Re: Water Pressure Gauges

water line for water pump psi is similar to the line that brings water pressure to your speedometer - there has been some discussion about teeing into the tell tale or plugging it - you need to do some research
 

Grayhorse

Cadet
Joined
Jun 29, 2005
Messages
29
Re: Water Pressure Gauges

Just tee into the flexible hose feeding the tell-tale. Your gauge will still give you a reasonable idea as to what your cooling system is doing. When you first install the gauge, plug the tattletale to get an idea what the full pressure is and compare it to factory spec's. Once you know you're at recommended pressure, just unplug the tattletale , note the pressure, and if it drops substantially during normal operation, you know you've got a problem. Mine runs about 30 plugged, and about 20 unplugged. Just a quick note about plumbing your gauge, use hard plastic 1/4" airline or something similar for running long distances to gauge. The softer rubber tubing normally used will eventually weather, crack, and bulge if it doesn't rub through first. Just use short pieces of rubber tubing (automotive vacuum/washer fluid hose) from the tee to the hard plastic line, and from the gauge to the same. The rubber hose will slip over the airline with a little lube. Plastic tee's and connectors are also available from automotive supplies.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Water Pressure Gauges

Here's what a Teleflex gauge hookup looks like in the tell-tale on a Merc. (7 PSI @ idle/ 17 PSI @ WOT).<br />
75c56ac4.jpg
<br />When installing a WP gauge you should also install a new water pump. Then you know what "normal idle" and "normal WOT" pressure is. Any deviation from normal is then an indication that impeller replacement is necessary. Just so you know, an engine can have good water flow but still overheat so this is not the only protection. A temp gauge and knowing that your alarm system is working is the other half of the equation.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Water Pressure Gauges

why not just maintain it as per the service manual and play?<br /> I have never,in 30 years, seen a pump failure on a well maintained rig.
 

snowmon

Seaman
Joined
Jun 23, 2004
Messages
55
Re: Water Pressure Gauges

wish i had a wpg when i ran over that friggin big old plastic bag that clogged my intake. of course i probably wouldn't have been watching the guage if i had it seeing as i didn't see the damn bag either.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Water Pressure Gauges

snowmon<br /> my exact point.<br /> unless I am running a jackplate making above standard changes in motor height temp guages and water pressure guages on outboards are mostly teats on a boar hog.<br /> a well maintained system,including testing the temp switches and alarm systems is worth way way more.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Water Pressure Gauges

Yup -- just like the idiot lights on the dash of your car, the warning horn tells you what just happened. The purpose of the water pressure gauge is to alert you to a "change" from the norm. Noting idle and WOT water pressure with a new impeller serves as the bench mark. Any change from those readings indicates something is amiss. Loss or reduction of water pressure on a raised engine, or one that's trimmed up is also an indication that you probably need to be careful. Unless you have a universal joint in your neck and like to watch the tell-tale at speed, a water pressure gauge is a valuable instrument. Add the temp gauge and again note the idle and WOT temps and you now have a good way to keep tabs on what's going on with your engine. Obviously they serve no purpose if you never look at them.
 
Top