Gas Gauge

[Motorcycle Mayor]

I accidentally ran my 2017 ES all the way down to one bar on the gas gauge the other day. Well, actually, it was sort of deliberate: I wanted to see how much fuel it'd take to refill it from such a low level .

Filling the tank from one bar took 4.6 gallons of gas...which doesn't seem consistent with the tank holding 6.6 gallons.

So, is the gas tank not actually 6.6 gallons? Or is the gauge that non-linear? Or something else? 

Just curious.

 

[Ignacio]

 Or is the gauge that non-linear? Or something else?

Probably one or both.  One bar could be almost two bars...and the remember goes into countdown mode with the reserve. One bar is is not actually that close to empty.

And you didn't say exactly how full you filled it at 4.6. If the nozzle was shoved in all the way and clicked off...that's not full.  Even if you lifted up and goosed it a time or two...there's some headspace.  Or did you literally squeeze in the last 1/10 of a gallon until the cap would barely close.

The actual FULL tank is very close to 6.6 on these bikes....probably within =/- 0.2 or so.

 

[escapefjrtist]

Sounds pretty close to how my '15 fuel level displays. When the fuel mileage count-up begins, the bike still has ~1.5 gallons left in the tank. You can also reference the "Range" display which I've found is surprisingly close to reality...at least on my '15. YMMV - literally!

~G

 

[Panman]

My old 07 is about 4.8 gallons when the blinky light hits.

 

[RossKean]

Keep in mind that the last bar disappears with about 1.5 gallons left and goes to the flashing bar with the count-up odometer - enough for 50-60 miles as long as you aren't abusing the throttle or sitting in traffic.  On both my Gen II, this was pretty consistent and I found the gas gauge to be as linear as on most other vehicles as long as I fill it completely (otherwise the first bar is less).  About a fifth of the total capacity is after you hit "reserve".  Gen III is a bit different but I think linearity and the reserve amount are similar.

People have been known to "adjust" their fuel sender by bending the wire for the float to make it more "correct" but I would not recommend it unless yours is reading very differently than most.

 

[HotRodZilla]

If you read the manual, the gauge goes to the "F" reading when there is approximately 1.5 gallons of fuel left. F is basically your gas light.  That 1.5 gallon number is very approximate, but if you run the bike long enough, it will end up taking 6.6 gallons to refill. As it is, you had ~80 miles of fuel left or about 1/4 of a tank. 

 

[mcatrophy]

I accidentally ran my 2017 ES all the way down to one bar on the gas gauge the other day. Well, actually, it was sort of deliberate: I wanted to see how much fuel it'd take to refill it from such a low level .

Filling the tank from one bar took 4.6 gallons of gas...which doesn't seem consistent with the tank holding 6.6 gallons.

So, is the gas tank not actually 6.6 gallons? Or is the gauge that non-linear? Or something else? 

Just curious.

This might cause you more confusion than answers, however ...

Some time ago, I did a test on my 2010's gauge. I don't think the tank or its internals have changed from 2006 since, so this may still be relevant. and my 2018 behaves the same as my 2006 as well as the 2010.

I was wanting to try to linearise the gauge, as the indications towards empty are less helpful, but more critical. In the end I didn't succeed because of the results I got from a detailed measurements of its characteristics. To sum up, this table shows fuel quantity remaining against gauge bars.


 


 


 


 


 


 


 


Bars 0=F


Litres


Gallons UK


Gallons US


 


 


 


 


0


0.00


0.00


0.00


 


 


0


5.90


1.30


1.56


 


 


1


6.38


1.40


1.69


 


 


1


6.95


1.53


1.84


 


 


2


7.50


1.65


1.98


 


 


2


9.00


1.98


2.38


 


 


3


11.00


2.42


2.91


 


 


3


13.00


2.86


3.43


 


 


4


14.00


3.08


3.70


 


 


4


15.00


3.30


3.96


 


 


5


15.50


3.41


4.09


 


 


5


16.25


3.57


4.29


 


 


6


18.00


3.96


4.76


 


 


6


20.00


4.40


5.28


 


 


7


22.00


4.84


5.81


 


 


7


24.00


5.28


6.34


 


 


8


24.80


5.46


6.55


 


 


8


25.30


5.57


6.68


 


 


 


 


 


 


 

I tried to show the quantity at the limit of each bar's range, so there are two quantities at each step, there is obviously uncertainty on the precise quantity at which the gauge switches from one reading to the next. I show two places of decimals, this is (of course) wishful thinking in terms of absolute accuracy, just the result of conversion from fluid ounces at the lowest part, and fuel pump readings at the upper. There is uncertainty on the limits of each bar's quantity as I was measuring with increments of fuel added between each reading. All measurements were made with the bike on its centre-stand (it reads significantly lower on the side-stand), and the engine not running (doesn't seem to make much difference running or not).

All quantities I show are available to use, I "emptied" the tank via the fuel pump, so it's not as if I started with a totally dry tank and measured what was poured into it.

A graph showing quantity of fuel against bars displayed. Note that the vertical lines show the quantity range at one gauge indication, the sloping parts show the uncertainty in my measurements between where the gauge changes from one reading to the next.



While there is some variation bike to bike, certainly in my experience of four FJRs, they all behave about the same.

The way I did all this can be read here.

 

[rbentnail]

My old 07 is about 4.8 gallons when the blinky light hits.

My current '07 has always been 4.8 gallons when the blinky light comes on. Been that way since new.  OP needs to RTFM to learn how the gauge works fully then run until he/she/it gets a blinky light. 

 

[SkooterG]

Sounds pretty close to how my '15 fuel level displays. When the fuel mileage count-up begins, the bike still has ~1.5 gallons left in the tank. You can also reference the "Range" display which I've found is surprisingly close to reality...at least on my '15. YMMV - literally!

~G

Georgie Porgie - I am calling foul on the shite you posted above.  One of my several peeves with the Gen III+ is that the range countdown is not accurate.  And if it's not accurate, why have it?  On my '13, '14, '16 (I had), and '17, when it hits '0' I still have 20-30 miles of fuel left.  Consistently.  Like clock work.  I go by the flashing reserve.  When that starts flashing I know I have 50-75 miles left depending on conditions.

 

[escapefjrtist]

Wouldn’t you want the range a little pessimistic so you’re not pushing (and shortening fuel pump life) all the time? My experience says the range takes the tank to (or slightly into) reserve. Once the flashing count-up begins you’ll still have 40-60 miles left before pushing.OTOH, I’ve not nearly had the number of POS GEN IIIs as you...so I’ll defer to your extensive knowledge base!

~G

 

[SkooterG]

When was the last time you heard of a fuel pump going bad?  I can't recall a single one.  Nope, if I have some type of gauge, or indicator, I want it to be accurate.

 

[hppants]

I'm on my 3rd FJR.  On each one, I have conducted two experiments - one on purpose, the other unintentionally:

1.  For each bike, when I knew I was close to hitting "reserve", I circled a gas station so that I could know with a fair amount of accuracy, how much fuel I had left at reserve.  On my 2005 Gen 1, at the reserve, I burned 4.8 gallons.  On both of my Gen 3 bikes (both '14s), it was 5.0 gallons.

2.  I've run out of gas on each bike.  On the Gen 1, and my first Gen 2, when it runs out, it takes 6.6 gallons on the side stand to fill it to the neck (hole where the nozzle is inserted).  I mean, that tank was dry.  On my current Gen 3, it will only take 6.3 gallons.

The "range indicator" is pretty accurate, but the information I gathered is better.  I know on my current bike that once reserve hits, I've got 1.3 gallons of useable fuel left.  That equates to 40 miles for planning purposes, and probably 50 miles at the absolute most before I start walking.

 

[HotRodZilla]

Georgie Porgie - I am calling foul on the shite you posted above.  One of my several peeves with the Gen III+ is that the range countdown is not accurate.  And if it's not accurate, why have it?  On my '13, '14, '16 (I had), and '17, when it hits '0' I still have 20-30 miles of fuel left.  Consistently.  Like clock work.  I go by the flashing reserve.  When that starts flashing I know I have 50-75 miles left depending on conditions.

1: The count up feature on the FJR is stupid. I don't care how many miles I have gone since the light came on. I want to know about how many miles I have left. Every vehicle with that feature does that measurement based on average MPG over a certain period of time.

2: Because I can count and read a fuel gauge, I have only ever run one vehicle with a counter to the "0 Miles Left" indicator. I'm glad that thing was pessimistic because we were 4 or 5 miles from a gas station when the counter hit zero. Essentially there is an idiot margin built into the idiot warning.

3: I have gone as many as 70 miles on my F-stop and as few as 20. On the way to TN with Patch, we were riding against the wind and I was getting maybe 26-29mpg. My F warning came on and 20 miles later the bike stuttered at the bottom of a freeway off-ramp. It ran enough to get me to the fuel pumps and I put 6.6 gallons, maybe 6.7 in the tank. I tend to over fill mine going into the air reserve, a lot.

 

[RossKean]

1: The count up feature on the FJR is stupid. I don't care how many miles I have gone since the light came on. I want to know about how many miles I have left. Every vehicle with that feature does that measurement based on average MPG over a certain period of time.

I like the count up. From the start of the count up, I know I can do 70 miles if I am driving fairly conservatively.  If I am further than I like from a gas station, I will reset the average MPG readout so I can monitor it more closely.  A bit over 1.5 gallons. Amounts to the same thing as a count down.

 

[Mortenk]

On my 2016, each fuel segment equals roughly 25-30 miles depending on riding style - and it is fairly linear (bar 4 lasts a little longer, and bar 3 a little shorter). So, while riding back roads the last segment will start flashing after approx. 240 miles. The gauge basically only covers the "main" tank, which is approx. 5 gallons. Each segment is basically 0.625 gallon (US). Once flashing kicks in, and the count-up starts, I know that I have 50-60 miles left to empty, which is very accurate as long as you are driving under normal conditions.

The Range indicator is useless to me as it is all over the map and shows LO with about one gallon left (40 miles to empty). I never fill up until count-up hits at least 20, but sometimes 40 mi, which means that I typically add 6 gal or a little less.

 

[RossKean]

When was the last time you heard of a fuel pump going bad?  I can't recall a single one.  Nope, if I have some type of gauge, or indicator, I want it to be accurate.

I agree with SkooterG.  Fuel pump failures in FJRs are EXTREMELY rare.  I certainly don't deliberately run until I am at fumes but I certainly don't worry about damaging my fuel pump!  Why should a fuel pump get especially hot anyway?  Seems to me that would be a major design flaw for something that is in contact with flammable liquids and vapors!!   Hot enough to damage the pump - I don't think so; especially since electric motors often run pretty hot without self-destructing.   I can just barely understand that the fuel may lubricate the pump to some extent but even a tiny amount of remaining liquid gasoline would do that.  Once the liquid is gone, the pump won't be running anyway.

 

[Ignacio]

Reminder: This thread is about the FJR Gas Gauge. Please stay on topic.

Thanks.

The Management