GL1100 "sagging" fuel guage

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my 77 Is at empty go to fill her up it only takes 2 1/2 gallons, So I know I have just a little after the E. And before I filled up I thought What crappy gas milage,

I would check your wiring under the seat on top of the sending unit, Mine wouldn't read with the 7 volt regulator, so I by passed it and run 12 volts to it, seems to work fine, I have an extra gauge just in case I fry this one, I did put a 7 volt reg, in for the temp gauge,

So I'm not sure how accurate these things are, It's not hard to get to the sending unit, just take off your seat, and and there it is, Theres just a little spin ring on top with the two wires, Just make sure your gas level is below that sender, Or that could get messy,

With the sending unit out, plug it in, and you'll have to ground it to the tank, Then you can move it up and down by hand, watch the gauge and see what it does,

Could be bad wiring, bad ground, or bad gauge, I'm not so sure about the 7 volt reg, set up.

Good luck

imported post

Hello,

I have a '78 GL1000 and recently had the same type of problem with the accuracy of the fuel guage. I would fill the tank, then after riding for awhile the guage read empty, but filling it up took only ~2 gallons. I ended up removing the sending unit, checked the float for leaks (not the problem), then removed all the sediment. I ended up opening the unit cover (it was simple to remove by bending some metal tabs . . . carefully, this old stuff) to gain access to the wiper, then cleaned it with a good dose of contact cleaner. Again there was sediment to remove. You have to be careful not to break the small wire between the windings the wiper rides on and the top of the sending unit.

Once all was cleaned, connected the wires back up, switched on the ignition and checked the guage while moving the float arm (you have to give the guage time to react). The cleaning got rid of the dead area along the windings. Put it back together, dropped it back in the tank and it has worked fine ever since.

Something you may want to try before searching around for a new or used sending unit. For me it was the challenge to get it working again if possible. Hopefully your bike uses the same type of unit.

Don