Gas Guage !@#$%?

Khunajawdge · Mar 29, 2009

Yesterday, I leave the barn with 8 bars showing. The Trip ODO is zeroed out. 231 miles total for the day.

I Ride to pick up Steve. He fills his FJR 8 miles later than mine and zeroes out his ODO.

We commence riding. About 30 miles out, I look at my gas guage and it reads 4 bars = WTF?

At the halfway point, I am at 2 bars. On the way back, my reserve starts flashing and goes to 62 miles into reserve = It never made it over 40 before?

I RUN OUT OF GAS! Steve runs to town and gets me some gas. He's got like 2 bars showing and has plenty of gas. After putting in a gallon or so in my FJR, I make it to the station, fill it up, and I only show 6 bars = now what? I'm guessing I won't be able to trust my gas guage to be even remotely dependable anymore?

Obviously, I didn't have a full tank when I started the day as was falsely indicated when 8 bars showed in the early AM. Based on that, I assumed I had a Full tank. But why did the guage start reading a couple bars short of where it has always read? Anybody have trouble with the "relative" accuracy of their gas guage?

TIA

'05 blue 46,000+ miles

dcarver · Mar 29, 2009

My guess is the sender is going bad. IIRC, some folks that have added bulkhead fittings had pix that clearly showed the sending unit and the little wiper arm that contacts resistance elements thus changing the voltage drop as read by the ECU or perhaps directly by the gauge, not sure.

Looks like soon you'll have the tank off and pulling the pump out? If so, let me know when, I'll take pix

cota95 · Mar 29, 2009

I don't have any problem with mine except that if the bike is on the side stand it will sometimes show lower than what's in the tank once I get rolling. Yesterday I went on reserve and when I filled up I squeezed in 5.1 gals.

Joe2Lmaker · Mar 29, 2009

I'm not sure how to be both encouraging and at the same time a circling vulture, but I'll try...

Good luck. I hope the problem is something simple like just cleaning the contacts or something.

If you do need a new fuel pump assembly, PM me. I have a use for your old GenI fuel pump flange.

RadioHowie · Mar 29, 2009

Joe2Lmaker said:
I have a use for your old GenI fuel pump flange.

Are you STILL working on that project? Hell, I thought you'd be into mass distribution by now.

BTW, after I put in my "new" fuel pump, hopefully this week, you're first on my list to get my old flange.

PM me with shipping details, m'kay?

RsvlFeej · Mar 29, 2009

Khunajawdge said:
We commence riding. About 30 miles out, I look at my gas guage and it reads 4 bars = WTF?
At the halfway point, I am at 2 bars. On the way back, my reserve starts flashing and goes to 62 miles into reserve = It never made it over 40 before?

62 miles on reserve is actually very close to what max range should be - definitely doable if you're at altitude. I've made it 55 miles w/o running out of gas (as a general rule, I usually don't go more than 20 miles on reserve).

As to your fuel gauge, when mine went, it went way wonkier than yours. I thought I had a fuel leak, as it dropped from 6 bars to 2 in about 10 miles - so, after a quick change in route planning to fill up earlier than planned (and with a careful sniff for gas), the gauge wouldn't register full and again dropped like a rock. I depended on visual checks for the rest of the trip.

Bad news is, the sender and fuel pump are considered a single unit by Yamaha, good news was, I was still under warranty at the time.

Good luck,

RsvlFeej

Joe2Lmaker · Mar 29, 2009

RadioHowie said:
PM me with shipping details, m'kay?

Cool! PM Sent.

I'll get started on another batch of fittings. I hate to see those GenI flanges go to waste!

RadioHowie · Mar 29, 2009

Joe2Lmaker said:
RadioHowie said:

PM me with shipping details, m'kay?

Click to expand...

Cool! PM Sent.

I'll get started on another batch of fittings. I hate to see those GenI flanges go to waste!

AHA!!! So you ARE getting ready for mass distribution! :yahoo:

Khunajawdge · Mar 29, 2009

Thanks for ALL the replies!

It ALL helps when an FJR owner is having a problem.

Will be pulling the tank off soon. I'l try to clean any contacts that I find, but I'm heading into the unknown (again)?

Don, "if" you want to take pics, tomorrow afternoon around 4:00PM might be good for me? Send a PM or call if you are coming to LO, and I'll pull the tank off before you arrive.

Might have a Gen I flange for you Joe2Lmaker?

RadioHowie · Mar 29, 2009

Khunajawdge said:
Might have a Gen I flange for you Joe2Lmaker?

Don't get TOO itchy to buy a new fuel pump just for the gauge float assy.

I might have one of those available REAL soon.

odot · Mar 30, 2009

What the **** does "wonky" mean?

user 6393 · Mar 30, 2009

odot said:
What the **** does "wonky" mean?

Wonky - EskiTexans click here

ionbeam · Mar 30, 2009

Khunajawdge said:
...Will be pulling the tank off soon. I'l try to clean any contacts that I find, but I'm heading into the unknown (again)?

Be careful cleaning the fuel level sending unit!!! This is what the unit looks like (photos by miikka555), the black squares are the actual resistive material and the silver is the conductive pickup. Any abrasion to these two items will FUBAR the sender. You can carefully bend the arm that the float is attached to and adjust the sender level.

What bothers me is the sudden onset of your problem. There is a chance that a load of contaminated gas could have left a coating on the resistive material and/or the wiper on the float arm. I would suggest a tank of Techron before pulling the fuel pump assembly.

Another possibility is the float may have sprung a leak and now is a low rider in the tank.

Yet another possibility -- please take this one seriously, no kidding, in spite of how it is going to sound-- If your tank had a venting problem it can buckle. It may pull the bottom of the tank up, which you can only see if you pull the tank. Sometimes, from the top you can see the two indentations that run along each side of the tank are now deeper and run the entire length of the tank. This is unusual but not unheard of. I've seen a tank that this happened to. This will pull the pump up toward the top of the tank, causing a reading error and reduces the volume of the fuel tank.

If you do pull the pump assembly out, carefully inspect the resistor/silver conductor area looking for signs of wear or damage. In the end, the sender may simply have gone bad, again unusual but not unheard of.

Have you been following RadioHowies gas tank exploits caused by water in his tank?

Khunajawdge · Mar 30, 2009

ionbeam said:
Khunajawdge said:

...Will be pulling the tank off soon. I'l try to clean any contacts that I find, but I'm heading into the unknown (again)?

Click to expand...

Be careful cleaning the fuel level sending unit!!! This is what the unit looks like (photos by miikka555), the black squares are the actual resistive material and the silver is the conductive pickup. Any abrasion to these two items will FUBAR the sender. You can carefully bend the arm that the float is attached to and adjust the sender level.

Thanks for the pic Alan. I really appreciate the effort you put in here. Would have had no idea how complex this thing was before seeing that pic. On my older ZG 1000 Concours with a gravity feed/vacuum operated petcock, the sending unit was easy peasy compared to this piece of hardware of the post space age.

FJRinSJC · Apr 8, 2009

I've had gas gauge problems for a long time now, and am glad to have read this thread. Mine is an '05 FJR too, and basically, my gauge reads lower than actual. When I top off the tank, I never get full bars. Always 1-2 bars down, sometimes even 3 down. I've brought it in to my neighborhood dealer to fix with the Y.E.S. plan. I've had both the instrument cluster and the entire fuel pump replaced, but still have the same problem. Before this problem started, I used to routinely get full bars after topping the tank off, and usually don't get the reserve light warning till close to 200 miles. Nowadays I get it on very early, say 120 miles or so. Then when I pump gas in, it's usually like 4.6 gallons or so.

ionbeam Posted Mar 30 2009, 10:05 AM

Yet another possibility -- please take this one seriously, no kidding, in spite of how it is going to sound-- If your tank had a venting problem it can buckle. It may pull the bottom of the tank up, which you can only see if you pull the tank. Sometimes, from the top you can see the two indentations that run along each side of the tank are now deeper and run the entire length of the tank. This is unusual but not unheard of. I've seen a tank that this happened to. This will pull the pump up toward the top of the tank, causing a reading error and reduces the volume of the fuel tank.

I wonder if this might be the solution for me?? My gauge problem didn't start, until the day I got gas at STP in Woodside. I heard a whoosh sound when I opened the tank up, and after topping it off, it never read full bars. Been like that ever since...

ionbeam · Apr 8, 2009

FJRinSJC, you should check your tank and be sure that it hasn't imploded (had the bottom deform and pull up). If your gas gauge had a sudden onset to the erroneous reading issue, a deformed tank is highly suspect. The big whooshing noise is persuasive information.

Also, the gas gauge gets its voltage from the meter assembly, which you have had replaced. The signal between the meter assembly and the fuel pump assembly goes through Sub-Wire Harness 1, the schematic shows a 'A' with a circle around it on every wire that passes through this connector. Both the signal and ground for the gas gauge pass through this connector (Green/White & Black/White wires). This is the infamous connector under the tank that has shown pin corrosion in many FJRs, this would definitely cause your gas gauge problem.

RadioHowie · Apr 8, 2009

FJRinSJC said:
I wonder if this might be the solution for me?? My gauge problem didn't start, until the day I got gas at STP in Woodside. I heard a whoosh sound when I opened the tank up, and after topping it off, it never read full bars. Been like that ever since...

"Whoosh" means poor venting. And it's possible....very slightly possible, mind you....that high pressure inside the tank may have collapsed the plastic float on the end of the gauge arm, causing it to crack, fill up with gas, and ride low in the tank like Ionbeam said.

SkooterG · Apr 8, 2009

RadioHowie said:
"Whoosh" means poor venting. And it's possible....very slightly possible, mind you....that high pressure inside the tank may have collapsed the plastic float on the end of the gauge arm, causing it to crack, fill up with gas, and ride low in the tank like Ionbeam said.

Dude. What kind of mota you been smoking and where did you pull that silly fantasy-land hypothesis from?

ionbeam · Apr 8, 2009

Dude. What kind of mota you been smoking and where did you pull that silly fantasy-land hypothesis from?

Recently RH and I have had a One-Upmanship competition going. I crash my engine via the CCT, he craps his fuel pump AND crashes his engine. I tell poor FJRinSJC that he may have collapsed his tank and RH shows up to say he imploded his float, filled it with gas and sunk it.

RH is stressed and distraught, cut him some slack. Ok, times up, carry on... :lol:

Gas Guage !@#$%?

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