Fuel Starvation 33 mi into reserve

[John_Dumke]

Since reserve is supposed to have 1.45 gals. I thought I would avoid the gas station for a few more miles. At 45 mpg, and 1.45 gals in reserve. I should be able to go at least 60mi.

But at 33 mi on the odo. I noticed a cracking sound coming from the cat, like when the bike is warming up and too much fuel is getting dumped into the cat and causing it to burn and crackle. Then I got on it and there was a noticable fuel starvation as the bike would not pull hard like normal.

I got to the gas station and filled up the tank with 6.12 gallons of gas (measured at the bottom of the filler neck). Manual says 6.61 gals is capacity. So depending upon how they measure, it looks like I still had 1/2 gal left. Or the reserve milage isn't as accurate as I would like to think. After the tank was full, the bike pulled normally.

Anyway, I guess the moral of the story is that the FJR gets a little finicky when the gas gets low.

 

[Ignacio]

It could be a difference between generation of bikes and not sure where you got 1.45 gallons from, but in my experience if the tank is 6.6 gallons my Gen 1 is maybe 1 or 1.1 gallons. I was into the reserve 33 miles when I then filled with 6.33 gallons as full as I could fill it.

I'm sure they'll vary as well between bikes.

At least you know now likley on your bike where the reserve is.

 

[SkooterG]

Yeah, reserve on Gen I bikes is 1.1 gallons. Though it was unchanged for Gen II?

I have filled my FJR with 6.0 to 6.3 gallons on many occasions with no ill effects. That usually gets me 30-50 miles into reserve.

Except for my crashed FJR. Ever since crash #1 the fuel gauge has not been normal. Now reserve comes a flashing more quickly, but I can ride 70 miles or so while in reserve. Obviously, the knock had an effect on it's calibration.

 

[radman]

The float arm for the fuel tank sender is adjustable by simply and carefully bending it. In this way, you can adjust it for whatever reserve capacity you want to have. Fluctuation in the various riders bikes is most likely also due to this-unless the setting at the factory is spot on across the line, there will be discrepancies. Remove the tank, remove the pump/sender, and adjust to your liking.

 

[Ignacio]

So, if my reserve light goes on at 160 miles it might be because of a bent float arm and not because I've twisted the grip for the past 80 minutes to cover that distance? And I just thought I was only getting 26 mpg on that particular segment.

 

[radman]

Well, haw haw, don't that beat all! Actually, the range on the gauge, or the sweep as it were, is still intact, to a degree. Bend the arm too low, and it will take a while before the gauge begins to react to the lowering level in the tank, and you could run out before reserve is even displayed. Conversely, move it too high, and reserve could begin flashing with two and a half gallons in the tank. Subtle tweaks will get it just right for those who like a 1-1 1/2 gallon comfort level. Oh, and I've gotten mileage that bad with Frank, possibly worse, when spirits were running high. Not germane to the issue.

 

[mdisher]

Well, I don't know where my float is bent too...

I hit reserve typically around 190 miles give or take. At that point I've never been able to get more than a hare over 5 gallons in it, but it's usually 4.8-4.9. So my reserve should be around? 1.6 gallons right? I've pushed 30 miles into reserve a couple times but that's as far as I've gone.

05BlueDevil and I filled up at the same time a couple weeks ago and we were both within 2 miles of each other into reserve when we stopped (around 20 miles into it if I recall correctly)

 

[radman]

Well the gauge itself just reads whats fed into it. The gauge sender is a varying resistor to ground, the arm simply runs a contact over a coil, like so. Not a Feej unit, but good for illustrative purposes.

You can see how the position of the float in relation to the sender itself would vary what the sender reads.

 

[SkooterG]

Here be the FJR's..........

You know, it's also possible I bent it while removing and reinstalling it while doing my fuel cell bulkhead fitting project. That was done just before my crash at around 29k. Getting the fuel pump in and out was a tight fit and a bit of a puzzle. Regardless, I attributed the *calibration* issue to a bent float rod. I know on my previous Connie, I bent the fuel sending unit float rod to adjust the fuel gauge to read more accurately as radman describes. If I ever have my fuel pump out again I will probably try to readjust this one back closer to *normal*.

I just adjusted to it, and have lived with it - 95k on th FJR now. I know it freaked Skiwi out when he rode my FJR back from Nevada a couple months ago after crash #2. I forgot to tell him about it and out in the middle of nowhere he thought he was going run out of fuel a couple times. I can't remember exactly, but I think reserve typically comes around 190-200 miles now, but as I said, I now have a BIG reserve.

Interestingly, the characteristics on FJR#2 are identical to FJR#1 before the anomaly started, so I am guessing these things are pretty consistent coming from the factory. Reserve comes around 230-240 miles depending on various factors, and I can safely go 30 miles into reserve and then fill the tank with around 6.0 gallons, leaving a little bit of room. I do tend to consistently "top off" to the max when filling, so I think I add a tenth or two to the FJR's total fuel tank capacity. And then there is the fact that FJR#2 does NOT have a PCIII installed so my fuel mileage is back up to where FJR#1's was before the PCIII. Low to high 40s. On one recent tankful with a lot of easy miles, I filled with 285 miles on that tank. Think I put 6.3 gallons in on that fill up, so theoretically, I could have gotten 300 miles on that tank. Barely.

 

[FJRocket]

I went 40 miles into my flashy thingy this past Sunday on my AE. I wasn't exactly holding back on the throttle. Sorry, don't remember how much gas I put in. I try not to look at the pump after I throw the card through the slot. It's painful paying more for my motorcycle tank fill up than my Firebird used to cost. Of course that was a few decades ago. But I digress....

I've gone 47 weening it. On BOTH generation bikes I've routinely gone low 40s. Not run her dry yet.... knock wood. :headbonk:

 

[Wilson]

Some bikes have two seperate systems for measuring fuel level in the tank. One float type sensor for the fuel gauge and a sensor in the fuel pump for low level or reserve indications. I am not sure what system is on the FJR. I will check into it.

 

[Bounce]

i didn't see mentioned the fact that not all the fuel in the tank is usable. there will be some at the bottom you'll never reach.

 

[Fencer]

Well, I don't know where my float is bent too...
I hit reserve typically around 190 miles give or take. At that point I've never been able to get more than a hare over 5 gallons in it, but it's usually 4.8-4.9. So my reserve should be around? 1.6 gallons right? I've pushed 30 miles into reserve a couple times but that's as far as I've gone.

pretty much the same here. done up to 40 on reserves and still had 1/2 gal at least,

 

[SkooterG]

i didn't see mentioned the fact that not all the fuel in the tank is usable. there will be some at the bottom you'll never reach.

True. But looking at the design of the fuel pump and pick-up and the shape of the tank, I think it will be a insignificant amount. And it's entirely possible that when Yamaha gave their 6.6 gallon tank capacity, they were talking about *useable* fuel.

I know that in my old Connie, the last .5 gallon of fuel of teh 7.5 gallon tank was most definitely NOT useable. Don't ask me how I know this.

Well, I don't know where my float is bent too...
I hit reserve typically around 190 miles give or take. At that point I've never been able to get more than a hare over 5 gallons in it, but it's usually 4.8-4.9. So my reserve should be around? 1.6 gallons right? I've pushed 30 miles into reserve a couple times but that's as far as I've gone.

pretty much the same here. done up to 40 on reserves and still had 1/2 gal at least,

Interesting. After getting FJR#2 and seeing that the fuel gauge acted indentically to FJR#1, I thought they must all be pretty darned consistent. But that does not seem to be the case.

Have any of you had your fuel pump out where it could have been tweaked?

 

[fjrchooser]

Keep in mind the contact area swept by the fuel float arm is just a silk screened resistive film'painted' on. While it's pretty tough it's also really thin and on a nearly empty tank that float arm is bouncing through much of its sweep range at a good clip with little fuel to buffer movement nor cool the fuel pump.

Another words, running low fuel consistantly is tough on both the sender and pump.

 

[SkooterG]

Another words, running low fuel consistantly is tough on both the sender and pump.

I disagree with that. I have seen this claim countless of times, but yet to hear of one fuel pump or sending unit failure.

I have run my 95k FJR down to fumes on regular basis with no problems other than that from other major abuse I have heaped on it.

And as far as I am concerned, the fuel pump is not cooled by the amount of fuel in the tank, but by the fuel flowing through the pump as it pumps it. So as long as you do not run it dry...........no issue.

 

[fjrchooser]

I guess you'd need to have a part of my job to see this on a regular basis Scooter- warranty analysis of driver information products for a major automotive supplier. As always, feel free to call BS and carry on in bliss.

 

[SkooterG]

I guess you'd need to have a part of my job to see this on a regular basis Scooter- warranty analysis of driver information products for a major automotive supplier. As always, feel free to call BS and carry on in bliss.

First of all..............relax.

Note my words "I disagree" and not "You're full of shit". Different meanings, no? "I disagree" means it's an opinion and I am completely open to some good information to further the discussion and perhaps learn something.

Second, sounds like you are in a position to gain some good insight into this, so why don't you share some of it? Failure rates of these components and resulting conclusions would be good some good information to banter back and forth.

Missing it, and regardless, I would find it hard to believe Yamaha would design a system with 6.6 gallons of fuel where using more than half (3/4?, 7/8?) would be damaging to the system. If it were, not only would I be extremely disappointed in Yamaha, but I would have expected to see reported problems with fuel pumps and fuel sending units on this forum. And I haven't. (Not that it's never happened.)

And as to what's *hard* or *tough* on a component or system - stuff like that can be argued forever with the absence of facts. Perhaps running the tank low is *harder* on some components, but perhaps those factors that make it *hard* are taken into account during the initial design of the system and the design life of those components under those conditions is 300 or 400 thousand miles, or more than other components on the FJR. Perhaps actual failure rates are so low to be considered insignificant.

We have seen problems with valve guides, the occasional cam chain tensioner and recently final drive seals, ignition switches, and of course TPS sensors. NOT fuel pumps or fuel sending units. I don't call those facts "BS" or "Bliss". You have information otherwise? Then by all means share it.

 

[HaulinAshe]

Personally, I find the additional 30-second delay needed to fill the tank with the full 6.6 gallons decreases my MPG unacceptably. Mostly because I am then forced to run even faster than normal to make up for the lost lap time. So I prefer to ignore the Odo, aim for a clear pump when the last bar blinks and pump without removing my helmet, gloves etc.

Sorry, that had NOTHING to do with this thread.