best guages to have

[83mulligan]

I just bought a new to me 99 crestliner super hawk 1700. It has the standard guages. Johnson 90 HP PLEEB (1999). Has the tach and engine warning lights guage, Speedometer (doesn't work or have pickup, don't need it), Tilt/Trim (doesn't work, don't need it), Battery Voltage, Fuel Gauge (not working properly), Two unused small gauge places.

My question is, what are the most practical gauges to have/install to monitor the big engine and keep it running well long term. I'm willing to throw out the tilt/trim guage and speedometer, and have two blank spots also. Lets hear your opinions on what I should have up there in the cockpit.

 

[riptide09]

Re: best guages to have

Ones that work.

 

[roscoe]

Re: best guages to have

tach, water pressure, volt

 

[saumon]

Re: best guages to have

tach, water pressure, volt

Agree. If you want a fourth, you can add water temp but not as critical as water pressure. For pressure, you'll need to memorize the pressure "curve" of your particular engine at various rpm with a new impeller and a working T-stat. That will give you the baseline to determine if there's a problem.

 

[83mulligan]

Re: best guages to have

anyone know if a 99 johnson 90 hp is already wired for a temp gauge?

 

[gm280]

Re: best guages to have

My wish for gauges differs from those post above. Yes, a Tachometer to keep track of the engine and the condition of the prop too. And yes, a good volt meter to verify that the alternator is working and the condition of the battery or batteries with a selector switch. But I don't recommend a water pressure gauge and here is why. You could very easily have great water pressure but still have a plugged flow. So if you rely on pressure to verify everything is working properly, it could be a wrong indication and failure will happen shortly for sure. My three gauge set would include Tach, Volt and Fuel as the minimum gauge setup. All the others are nice but certainly not needed... Speedometer, Oil Temp, Water Pressure, Trim Angle and so many others are mere eye-candy for the most part... A Tale Tell stream (Pee Tube) is so much more important to me then water pressure...

 

[Silvertip]

Re: best guages to have

Actually water pressure AND cylinder head or water temp gauges are needed if you are really interested in engine longevity. You can still retain the tell-tale if that is important to you. Water pressure gauges cannot plug because there is no water flow "through them". Speedometers work on the same principle but they fail to work because the tiny hole in the pitot plugs up. That's not an issue with water pressure gauge. Install the gauge and a new impeller at the same time. You then jot down idle, mid-range, and WOT water pressure readings. Any significant deviation from those numbers down the road is an indication of a problem. Water temp/cylinder head temp gauges are just as valuable on an outboard as they are in your car or truck. Voltmeter, tach and fuel gauges are the others that would then allow full monitoring of the all systems. If you have a four stroke engine, engine oil pressure is a critical gauge. But none of them are worth anything if you never look at them or understand what they are telling you. Unfortunately, many folks that experience an overheat or low oil pressure reading feel it is ok to run back to the dock. Those are indications that there is a problem NOW that needs to be addressed NOW -- not tomorrow. Calling for a tow is the immediate requirement which will save you the cost of a destroyed engine, unless it is already destroyed.

 

[gm280]

Re: best guages to have

Silvertip, I think you misunderstood what I was saying about a cooling system plugged. I'm not saying that the water pressure gauge or the tube leading to the gauge plugs. I'm saying that if you rely on a water pressure gauge for your cooling system function and for some reason the outlet gets plugged (the end of the cooling system not the gauge tube) it would still register pressure and give the operator a false sense that everything was okay. And dirt dabbers, mud wasps will build in those outlets quickly too. So unless you have some other way to verify the cooling system is operational, bad things will happen. So I would skip water pressure for my needs. Again a Tale Tell running is a great way to see that the cooling system is operational. And unless you have some warning indicator like a blinking red light or audible alarm, most people will never know there is any problems. How many folks look at their gauges in their cars...? Cruising along on the water will steer your attention more so then watching your gauges. Just simple Human nature...

 

[Silvertip]

Re: best guages to have

I didn't misunderstand at all. A plugged tell tale does not cause an engine overheat. Likewise, no telltale with normal water pressure tells you the telltale is plugged. Normal water pressure with normal temp gauge readings but no telltale also tells you the tube is plugged. All a telltale tells you is that you have water flow. It is no guarantee you don't have an overheat condition.

The alarm system will warn of an overheat but water pressure and temp gauges would provide a much earlier warning that something is amiss -- but only if you look at the gauges.