Gas Gauge Inaccurate

[Anonymous]

Just wanted some thoughts on why suddenly the gas gauge on my 1982 GS850G has become inaccurate after 38K miles. I noticed this summer during one of our long trips, that the gas gauge started reading incorrectly.
After a fill-up (topped off) I noticed once on the road the gauge would only read 3/4 full. This is pretty much the case as the fuel is used. The gauge reads about 1/4 less than it really contains. I know this based on using the trip odometer (always) as a true indicator of gas consumption. The 850 usually gets between 42-44 MPG when touring, so I know when to stop to refuel based on the trip. The gas gauge was just nice to have.

It's no big thing about the gas gauge. But it had been accurate all these years and I'm just wondering what could have happened.

Thanks in advance,
Dave P.

[Anonymous]

gauge

Thats what these things do you can pull it out and use an OHM meter to check for a dead spot in the reostat part of the sending unit, maybe the float also you have to pull it apart to find out, my advice is unless you got a new seal there don't mess with it

[focus frenzy]

follow the wires from the sending unit down to the connections to the wiring harness and clean or replace the connectors.
the brass of the connectors tarneshes and acts like a resistor and causes the gauge to read low.
this would be the biggest cause of a sudden drop in the reading.

also check the connnection in the harness to the instrument cluster.

normaly sending units work or don't work, the odds of the sending unit being the cause for a gauge now showing 1/4 lower than normal are pretty slim.
there is a slight possibility that it could be in the gauge it'self but odds are it is a wiring connection problem.

[Anonymous]

leaking

As well as the previous readings it could be a leaking float, although over time it would probably read empty all the time once it fills up or becomes saturated...Mike

[Anonymous]

gauge

Got to disagree Leon they read dead when the windings on the reostat plate break, usally they become dislodged from the plate there attached to, and contact another winding giving you a false reading, or a series of them have become dislodged like in my truck witch reads full then drops to 3/4 in about 2 gallons of usage then at half tank, then when really at half thank if reads empty, and at a 1/4 tank it starts to work again I took it out so I know that is what is wrong with it, my gs was doing simaliar pulled the unit same thing but I got lucky and got an NOS ebay unit