Fuel Management & Speed/Trip Gauges

[Pfu]

As I continue to fix components on my 2000 Grady White Gulfstream 232, I am looking at my gauges. The fuel management gauge is impossible to read (like an ink pen leaked) and thinking of replacing the gauge. The speed gauge always shows 0 mph and not sure how the trip portion functions.

Although I am on a decent size lake and not going offshore, the thought of high fuel prices makes me think the fuel management gauge may still be useful. Speed/trip not so sure with the gps built into chart hardware but would be interesting to match up (my phone, Fishhawk, and chart are all within 2mph). Thoughts on both? Good place to purchase fuel management gauge?

(Original Yamaha engines and gauges)

 

[Fishtales]

A common failure mode as I understand it. Try Sim Yamaha for a replacement.

 

[SkunkBoat]

I am mostly going to punt on this one because there are guys who will have better answers.
What I know is that

there are several models of gauges and you need to be specific.

the fuel management relies on the flow sensors in your fuel lines so they need to work and send signal to the gauge.

Speedometer runs from a pitot tube in the lower unit OR possibly you can connect GPS using NMEA0183. I can't remeber how mine was connected but I think it was GPS.

there are DIP switches that effect what the gauge will do.


Having GPH displayed is nice because you can find the best rpm/cruise speed/trim to get best fuel economy. Otherwise its a guess. You might be going slower and getting WORSE economy than going faster...

 

[Fishtales]

If the square ones..,

Yamaha Square Command Link Gauges For Sale

Two Tach gauges and one Speed/Fuel gauge for sale. All are in excellent condition and operate perfectly. $500 for all three or $200 each. I’ll pay shipping unless you need them overnight.

www.greatgrady.com

 

[glacierbaze]

GaugeSaver – LCD Gauge Restoration and Repair

gaugesaver.com

BTW, someone just posted Command Link gauges for sale here.

 

[Pfu]

Got the round one.(see attached pictures).

 

[seasick]

As I continue to fix components on my 2000 Grady White Gulfstream 232, I am looking at my gauges. The fuel management gauge is impossible to read (like an ink pen leaked) and thinking of replacing the gauge. The speed gauge always shows 0 mph and not sure how the trip portion functions.

Although I am on a decent size lake and not going offshore, the thought of high fuel prices makes me think the fuel management gauge may still be useful. Speed/trip not so sure with the gps built into chart hardware but would be interesting to match up (my phone, Fishhawk, and chart are all within 2mph). Thoughts on both? Good place to purchase fuel management gauge?

(Original Yamaha engines and gauges)

99 times out of 100, a no or incorrect speed indication is caused by a blockage in the pitot orifice and/or tube and not the gauge.
If there is no speed data, the gauge will not and can not calculate trip distance
Bear in mind that the even if the speed 'works; the pitot system is not very accurate. Use a multi function plotter for GPS speed. You can use NEMA interface (183) as mentioned but that signal would come from your plotter.

The fuel management system needs the flow rate signals form the fuel flow sensors. Before replacing and spending the money, first check all the wiring at the sensors. They can be removed and bench tested somewhat. They will be located somewhere between the tank pickup and the water separator. and look something like this

Yamaha - Conventional Fuel Flow Sender - 6Y5-85752-02-00

Yamaha - Conventional Fuel Flow Sender - 6Y5-85752-02-00

www.partsvu.com

 

[glacierbaze]

Are those four strokes? I would be surprised if command link gauges relied on a pitot tube for input. When I put a 2000 Yamaha four stroke on my Parker, the wiring harness had a plug available for engine data, including fuel flow. Just needed a cable from that plug to my networked GPS. Even more accurate than a flow sensor in the fuel line.

 

[seasick]

Are those four strokes? I would be surprised if command link gauges relied on a pitot tube for input. When I put a 2000 Yamaha four stroke on my Parker, the wiring harness had a plug available for engine data, including fuel flow. Just needed a cable from that plug to my networked GPS. Even more accurate than a flow sensor in the fuel line.

If there is no data link connected to a plotter, how would the engine know speed other than by a pitot tube. The pitot could be connected to a pressure sensor at the motor and present an electrical signal to the helm but you still need something to measure the speed.
I am not sure if the OPs motors are 2 stroke or 4. I had assumed 2 stroke but that might be incorrect.

 

[Pfu]

Two strokes.

I have the fuel senders (see picture prior to replacing all fuel lines) and wiring looks intact. Will try testing at some point this week but have little reason to believe it doesn’t work as gauge shows some data but 75% of screen is unreadable due to LED malfunction. Really think I just need new gauge.

Will trace out what the speed gauge has on the back.

 

[Pfu]

Two strokes.

I have the fuel senders (see picture prior to replacing all fuel lines) and wiring looks intact. Will try testing at some point this week but have little reason to believe it doesn’t work as gauge shows some data but 75% of screen is unreadable due to LED malfunction. Really think I just need new gauge.

Will trace out what the speed gauge has on the back.

Being out today was able to play with both gauges. Fuel usage definitely being consumed and reported to the gauge as can see the last digit changing while running on one engine while trolling. The speed flickered speed at 3-4 mph a few times (never double digits) and the time (?) of trip was clearly visible. Think new gauges will resolve most of the issues.

 

[seasick]

Maybe. It sounds like certain segments of the display might be dead, When you power up the guage, it should run through a quick self test and all segments of the display should activate for a few seconds. That will tell you if the display is OK.
The speed is probably a different story and I don't know how the system was originally rigged but the pitot sensor is not very reliable at slow speeds. Either you need to interface a signal from your plotter or in some cases a paddle wheel sensor is used.
I personally would not waste effort on the pitot sensor and suggest you look at the interface to your plotter instead.

 

[Parthery]

Don't replace the guages. You have a good setup.

They can be repaired. Remove them and send them to gaugesaver.com They are the real deal. $75 and your gauges will come back good as new.

I've used them on 2 different occasions. Worth every penny.

www.gaugesaver.com