Water Temp or Water Presure Gauge

[Stut]

1985 Johnson GT150
J150STLCOS
J6131018

Guys,

I would like to install some type of water gauge on my boat, but I'm not sure which one. I thought water presure would be the most informative, however, based on the most common gauge sales, water temp seems to be popular.

1) Which gauge is most useful, and more important?
2) What temperature should I be looking for on my GT?
3) What water presures should I see on my GT both at idle and WOT?

Thanks all!!!!

Stone

[JoePA]

Not sure as to the year of motor but I would think that you would have an overheat alarm if that would happen. I would go with a water pressure guage over the water temp guage. Reason being that you could always monitor the pressure while running WOT or any speed and if it is ever low or unstable you could save the engine before it overheats. The Rude gods will chime in I'm sure but That would be my .02 on what to do.

Do you run a jackplate?

[1993392]

I concur. Once the over temp alarm sounds, bad things can happen in very quick sequence.

[Stut]

Good, so I'm not crazy.....

I thought the same thing you fellers did, but why then do I get them impression that water temp is so much more commonly purchased? (Teleflex is quick to list RPM, Fuel, Speed, Oil, and Water Temp, but you have to hunt around for water pressure qauges. On Ebay, there are a MILLION water temp gauges, but very few water pressure.)

Plus, shouldn't a water presure gauge give you some indication of a water pump/impeller going bad?

And yes, my engine has the overheat alarm.

I really appreciate the help.

Oh, I do not run a jackplate. Transom mounted to the 2nd or 3rd hole down, I can't off hand remember.

Stone

[ChampioNman]

The Teleflex H20 Temp gauge is for an I/O you would get a cylinder tem gauge that afixes to the head and the probe touches the head. Most useful gauge would be the H20 pressure. Average range would be 4-8 psi at idle and anything over 18 is fine.

[201proride]

Why not do both the pressure and the temp. I like the temp as you can establish a base line of your temp at normal operation. Pressure to verify impeller performance. Temp to help indicate thermostat performance.

[WildeOne]

I have both and always have. The water pressure gauge clearly lets you know when the time has come for a water pump rebuild (pressure starts gradually decreasing at high power settings over time). Temp gauge shows overheating before the alarm sounds and damage is imminent.

[ChampioNman]

Depends how big your console is, if it is like most bass boats you are limited on gauge selection. The H20 pressure gauge is the most prevalant gauge. Overtemp is what the alarm/system check light is for.

[201proride]

Temp gauge good at indicating engine running cold as well.

[nola 521dvx]

A small point perhaps, but remember the water pressure gauge can be misleading if you happen to get some crud in the peehole - sometimes it can read higher pressure than it actually is, not a good thing. I don't have a temp gauge but would like one - water pressure is a very indirect measure of engine temp whereas sensors on the block would be a more direct measure.

[RUSTY63]

Water Pressure guage, as posted by the "C" man a temp guage on an outboard is not accurate, there is a sensor that bolts to the cylinder head.

But to each his own.

[Stut]

A 0-30psi water pressure gauge it is!!

Thanks for all the replies guys!!!

Stone