Resolved - How much fuel is left when the Yamaha alarm flashes - 375 Freedom

JustEnough

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Can’t seem to find the answer in the manuals, and I appreciate the help.

When the low fuel warning flashes (bottom bar) on the Yamaha screen on the 375 Freedom - does anyone know how much fuel is actually left in the tank? Similarly, when the alarm starts buzzing - is it the same situation?


Many thanks
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seasick

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There is no definite answer. If I see a flashing bar on my gauge, I worry if I am not close to home port.
Remembering that the tanks are not symmetrical a change of one bar does not relate to an absolute quantity of gas. In addition, there may be gas in the tank that sits lower than the lowest level of the sender. Whether or not you can use that gas depends on the height and position of the pickup and the angle of the tank.

The really tricky part is that unless you know when the number of bars changed, you don't know where in the range of a bar the level is.
For example, on my 208 the bars will change from two bars to one solid bar when there is about 20 gallons in the tank. When the single bar solid bar changes to blinking, there is about 10 gallons in the tank.
In this example, note that even though there are 8 possible bars on the level display, a single non blinking bar means I have somewhere between 10 and 20 gallons ( approximately).
The display will also read higher than the real level when on plane and cruising since the hull is angled bow up a bit.
When the boat comes off plane and settles down, my level can change by 2 or more bars.

The moral is: You can't get an accurate display of tank level due to the physics of the system I always add at a minimum the amount of gas I expect to burn that trip.
Fuel management systems are more accurate as long as you enter the correct data.
 

Hookup1

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One the older gauges there are 8 bars. The gauge "debounces" and slows the updates down. A solid bar is an 1/8 of a tank. When it starts to blink you are below 1/8 tank.

These gauges are approximate. Many factors to consider. Not like a car.
 

seasick

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One the older gauges there are 8 bars. The gauge "debounces" and slows the updates down. A solid bar is an 1/8 of a tank. When it starts to blink you are below 1/8 tank.

These gauges are approximate. Many factors to consider. Not like a car.
Mine is not at all linear. When the display changes from 2 bars to 1 bar, I still have 20 gallons of gas. That is twice what you get by using the 1/8 of a tank estimate..
 

JustEnough

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Lots of help guys – thank you. Bottom line is nobody knows for sure. Grady white service mentioned that the dealer might also have calibrated it.

First time it happened to me on Saturday in very confused seas and it seemed to drop quickly. Truth be told I had Boat US bring me 10 gallons because I was concerned I would run out in the Port Everglades channel. I’m filling up on Wednesday morning. I should have a pretty good handle then and I’ll report back.
 

seasick

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The most accurate display is with the boat at rest. If you are cruising and then come to a stop, you need to wait a few minutes for the display to stabilize.
Also note that passenger weight distribution can affect the reading. The more weight aft, the fuller the tank may read.
If you have the standard combo gauge with the 8 bars, there is no calibration ability. If you have the fuel management gauge, that needs to be calibrated.
 

drbatts

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Your 375 probably has trips. The pickups in the fuel tank(s) will at different levels. So in reality One engine will stall out first before the other engines. That way you won't instantly go dead in the water, but have a little time before the other engines stall out. With my 305 on long trips I will run my aux tank until my starboard engine stalls out or I have gone over 10 miles on the last flashing bar on the gauge.
 

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Use the Fuel management function. Your CL7 has that. I am sure you have some new MFDs on that boat too.
Tell it what you put in. Reset your trip. It tells you how much you burned and what you have left in gallons. Mine is accurate to 5 gallons over +200 burned.

You can set your MFD to display your Remaining gallons and RANGE.
Just use the gauge as a check against it in case you forgot to enter fuel or reset the trip.

You should never flirt with 1/4 of a tank. You have a 37 ft boat. Keep a tank full.
 

JustEnough

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Use the Fuel management function. Your CL7 has that. I am sure you have some new MFDs on that boat too.
Tell it what you put in. Reset your trip. It tells you how much you burned and what you have left in gallons. Mine is accurate to 5 gallons over +200 burned.

You can set your MFD to display your Remaining gallons and RANGE.
Just use the gauge as a check against it in case you forgot to enter fuel or reset the trip.

You should never flirt with 1/4 of a tank. You have a 37 ft boat. Keep a tank full.
So SkunkBoat spanked my ass a bit and I appreciate it. This particular boat is new to us and it was our first long trip so I did intentionally push it to get a baseline, but that was too close.

Fuel truck came to the house this morning and I took 297 gallons. That’s in addition to the 10 I took from Boat US.
My best guess is that when the bottom bar flashes and the alarm sounds - there is a reserve of roughly 20 gallons.
 
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