Fuel Gauge Does Not Like Super Full Tank!

[Guest]

Fellas-

Got a little pocket money yesterday, and decided to spend the day riding. I filled the gas tank all the up to the tippy top, and after pulling out of the station, I noticed that the fuel gauge was on empty.

Is there something about the extra-full tank that threw something off? I pulled the wires and checked the impedance on the fuel gauge and found it at 420 ohms. Yet, the manual states the higher impedance means an empty tank (120 ohms).

I noticed on my ride to school this morning that the fuel gauge is back to full (after loss of gas?). Interesting to know what is going on here.

Thanks.

[Steve]

Sounds more like a loose wire. Check the two wires at the back of the tank to make sure they have good connection.

.

[bakalorz]

Fellas-

Got a little pocket money yesterday, and decided to spend the day riding. I filled the gas tank all the up to the tippy top, and after pulling out of the station, I noticed that the fuel gauge was on empty.

Is there something about the extra-full tank that threw something off? I pulled the wires and checked the impedance on the fuel gauge and found it at 420 ohms. Yet, the manual states the higher impedance means an empty tank (120 ohms).

I noticed on my ride to school this morning that the fuel gauge is back to full (after loss of gas?). Interesting to know what is going on here.

Thanks.

If you search, there is a thread on the GSR on readjusting the sender inside the tank.
It used to have great pictures, but the descriptions are still good.

There is a sliding contact inside connected to a float.
It contacts a wound wire rheostat inside the tank.

Sometimes the arm its on gets bent enough to get loose, to where it no longer makes contact for part of its range.

When that happens, the gauge reads empty for part of the range.

To fix it, you bend the arm back.
You have to take the guts out.

Mine did it for a while, and I was going to eventually fix it, but then it spontaneously cured itself.

[2BRacing]

Maybe the tank has not been filled to the top for so long that the last part of the wire wound rheostat thingy inside the tank has become coated with foreign material. This "insulation" over the last part of the wire windings could cause high impedance, which could result in a false "empty" reading. However, when the fuel level drops slightly, the float makes contact with a "clean" part of the wire windings again, and the reading is back to normal.

The unit will have to be removed, inspected closely, and cleaned (or adjusted as per previous post).

[BassCliff]

Hi,

The fuel gauge send unit could need a little cleaning and/or adjusting. There's an article on my little website you might want to have a look at.

Fuel Gauge Send Unit Repair
(by Mr. Jethro)


Thank you for your indulgence,

BassCliff

[chuck hahn]

Theres little tabs that act as stops or rests for the arm, but i cant logically think of any reason the guage wouldnt read full. About all that makes sense is the dirty coil thing as men tioned before or maybe the float had just hung up on the side of the tank somehow.

[OldVet66]

I had one that did just that. They are hard to tweak so that they work just right. Last summer cured me of filling the tank too full. I used to fill it on the center stand but the sun on a black tank would make it leak when leaning on the kick stand until the level dropped. Now I fill it on the kick stand to just over the bottom lip of the flange that extends down into the tank. Seems to be just the right level. The gauge shows empty when I have a gallon left. I don't have a reserve so that is perfect. If the level doesn't drop to empty on a normal fill, I would leave it alone.