Gas Cap/gas gauge on 850

[Jason Adam]

I have the stock gas tank cap(locking rectangle) on my 850G. I replaced the gauges, and the only thing I'm missing on the new gauges is the gas gauge. I was wondring if anybody knew of a cap with a gauge in it, maybe an aftermarket gauge. Worst case, I use my trip-meter and the "res" when necessary... :-D

[duaneage]

welcome to the world of gas mileage math. Figure out your bike's total capacity and reserve limit while checking mileage for a while. I hoit reserve at 140-150 miles knocking around town and 165 or so on the highway.

But my late 1981 tank I installed on my 650G has a gas gauge sending unit so now I am in the gauge club!\\/\\/

Another alternative you may have is to mount a gas gause somewhere. IF you can get one from another Suzuki and make a small mounting box for it you might be able to do something. I think that most of the sending units in the tanks are the same and produce the same results.

[Jason Adam]

I think I confused You. I have a sending unit that works fine in the tank. I replaced my gauge cluster with new pod gauges. The new gauges have all the idiot lights, etc.. Just not the gas gauge. I was looking for a actual guage of some sort, that would tie into my existing sending unit, or, I have seen harly style choppers with gauges in the gas cap, but they are just round twist on caps.

[J_C]

Whoops! Yep, I was confused I deleted my post.

[themess]

My Suzuki manual, for GS650G doesn't show anything for the gas gauge for the 1981 standard model, but it has a bit on the gauge for the L, cruiser model. The "fuel gauge", which I think is the sender, is supposed to have the following resistance ranges:

Full - 1 to 5 ohms
half full - 25 to 40 ohms
empty - 105 to 100 ohms

For 1982, there are two pages of information

full - 3 ohms
half full - 32.5 ohms
empty - 110 ohms

Funny, these values are just the averages of the above values

The sender is not a simple resistance unit. 4 coils and a magnet are involved. The shop manual even has a diagram for the vector addition of the H fields of the 4 coils. I might have been able to understand this 35 years ago just after I studied this stuff in physics, but I am totally clueless now. So my only suggestion would be to find a fuel gauge from a bike being parted out and make a nice case for it to match your pods.

[duaneage]

THe gas gauge was added in late 1981, I think august. THe supplemental has it. They changed the wiring harness for the bike as well as the cluster. The speedo and tach are also 1/2 inch larger in diameter and the tach has the oil and high beam light.

The tanks are also a little different. The petcock is 4 inches forward on the late model tank.

To make the swap I modified the instrument cluster to work with the early bike, this way I could go back to original without having to replace the entire wiring harness. I also have a wiring harness for a late 81 but decided against swapping it.

The L cluster might be the same, they sure look close. Mounting might be different though,

If anyone is interested in how I did the swap PM me and I can provide detailed instructions but I warn you, it is a bit complicated. I had no problems other than a burned out light bulb, no fired wires or fires.