Add gauges or not?

[jhande]

My project boat does not have any gauges on it.
At least 2 gauges I would like is fuel and volts.
But I have an old metal portable gas tank that came with the boat. Is it even possible to install a sending unit in such a tank? Or can I find portable tanks somewhere with them? Only finding gauges built in, want the gauge on the dashboard.
Volt gauge would be nice to make sure the motor is charging the battery.
Would a tach or speedometer be useful even though I don't plan on cranking the motor to full speed. A pond I might fish often (closest to home and big bass) has a 5mph max speed, figure that's just basically no wake.
Any other gauges I might need to consider?

 

[JimS123]

Portable tanks should have gauges. Of course you have to go back and look at them - you don't really "need" it on the dash.

If you have a 12 V accessory plug (i.e. cigarette lighter) you can buy a nice digital voltmeter that plugs right in for about 5 bucks.

For your usage you probably can get away with just those 2. In the olden days most of us only had a gas gauge on the tank. Of course now, with a flat screen depth / chart plotter / GPS on the dash, I wouldn't be without the screen that has EVERYTHING recorded off the Mercury engine computer. For a project boat that can wait a few years.

 

[jhande]

Thanks Jim!

Someday I'd like to add a fishfinder and trolling motor.

 

[roscoe]

I would have a tach, water pressure gauge, and volts, in that order.

 

[calwldlif]

tach is a must for me.
tells many things besides engine speed.
it gives a baseline for health, unhealthy and feedback on proper
setup.
An idiot light is fine for volts unless you have some serious electronics and batt system.

 

[jhande]

I had all kinds of gauges in my old muscle cars and hot rods. My most useful was the vacuum even over the tach.

Didn't know there's a water pressure gauge especially for outboards. I'll look into that. Oh, maybe a water temp gauge might be useful????

 

[jhande]

WOW there's a big difference in price range.
Any recommendations on which brands are good or bad?

I'm trying to research info on my Mercury 500 outboard (can't find any tag/sticker on it).

Do all older (78ish) 2 cycle outboards allow water pressure and water temp hookups?

 

[racerone]

I do believe there is a plug on older 4 cylinder 50 HP models.----Find it on the water cover near sparkplugs.---Remove and install tubing for water pressure.

 

[jhande]

Thank you!
Any ideas for temp?

 

[JimS123]

If you have pressure you don't need temp, or visa versa.

Funny thing, I never had either gauge on any outboard I ever owned. Never thought I needed it. Then, after 50 years of owning boats, I installed a Mercury Vessel View system (which has literally EVERYTHING), and the first time out I picked up a plastic bag and the temp and pressure spiked. Without the readout on my dash (and me looking at it) I might have done some damage. I caught it even before the engine's buzzer went off.

At any rate, all this stuff is expensive. If you're on a budget a $5 voltmeter and a $99 depth finder will help avoid the most usual issues.

 

[jhande]

Thanks Jim

 

[Scott Danforth]

FWIW.....

there are gauge sender caps available. I believe that Rockford makes them. they screw in place of the tank cap and have a connector that you can run to a gauge.

Homepage - Leader in design and manufacture of gauges and sensors to measure liquid levels

The homepage is hard-coded for this site. Make edits to front-page.php

rochestergauges.com

and I believe Moeler has portable fuel tanks with gauge senders

they have the add-on module

Conversion Capsule – Mechanical to Electric |

www.moellermarine.com

as far as gauges - this is how I view importance
Depth
Tachometer
water pressure
fuel flow
oil pressure
oil temp
water temp
fuel level
trim angle
voltage
speedo
hour meter

(in that order)

on outboards, mostly simply had a tach and speedo growing up.

water pressure gauge gets plumbed in like you were tee-ing in a water supply to an ice maker

tach can come off the tach lead wires or get something like a tiny tach and use the inductive pickup wire you wrap around a spark plug wire.

voltage would go across the ignition wire and ground at the helm

speedo can be GPS or Pitot tube.

 

[Krazeehorse]

If you haven't done it already you might considered a small fuse bus under the dash to help power any new toys you might add.

 

[jhande]

Thank you so much Scott especially for the links.

I won't need oil gauges - it's a 2-stroke.

 

[jhande]

If you haven't done it already you might considered a small fuse bus under the dash to help power any new toys you might add.

Already making plans and a list of parts for all kinds of electrical gadgets.

 

[racerone]

Installing a new impeller every 3 years is one good step to take.----Resealing the gearcase is also one good step to make the 50 year old motor live a long happy life.

 

[jhande]

Good idea, thank you.

 

[jhande]

Hopefully last gauge question.

Would the depth gauge in a fish finder be okay or do I need a stand alone gauge?

 

[JimS123]

Hopefully last gauge question.

Would the depth gauge in a fish finder be okay or do I need a stand alone gauge?

A fish finder is the superior option. You have a "picture" visible at every glance. You can see where you've been and what's coming, rather than having to "think" about a number on a little digital dial.

Of course, if you are in deep water and then come upon a rock reef protruding 20 feet above the bottom, nothing is going to help you then.....LOL.

 

[jhande]

Thank you.

Yeah, had a close call while canoe fishing. I knew half of the pond as I normally fished one side. I decided to head way over to the other side and came across what looked like a boulder farmers wall. Dang things were less than a foot below the surface. Held my breath as I glided over it. Don't ever what a close call like that again or worse!