fuel level sensor

can anyone tell me how the fuel level sensor on a '79 D2 functions? It seems as though it should use the resistance of the fuel to keep the circuit to the light open until the level falls below the sensor.... maybe?
I've got two of them, but have no continuity between the wires through them when exposed to air or fuel. I can believe they are both faulty, but still would love to know how they are supposed to work.

anything at all is welcomed!

shortyyyyyy wrote:

can anyone tell me how the fuel level sensor on a '79 D2 functions? It seems as though it should use the resistance of the fuel to keep the circuit to the light open until the level falls below the sensor.... maybe?
I've got two of them, but have no continuity between the wires through them when exposed to air or fuel. I can believe they are both faulty, but still would love to know how they are supposed to work.

anything at all is welcomed!

According to the FSM, fuel gauges on both the '78D1 and '79D2 KZ1000 cafe racers are the same. Electrically operated by float inside fuel tank rising up and down changing internal resistance of the sender, thereby changing the amount of current flowing through the meter.

The gauge is of the bimetal type with a 7-volt voltage regulator built into it for over voltage protection.

The float attaches to a fuel level sensor from which a white/yellow wire and a black/yellow wire connect to the dash board gauge. The black/yellow wire also connects to the negative battery terminal. And a brown wire from the gauge connects to the positive battery terminal.

Gauge circuit check -- Disconnect the 2-pin connector to the sender underneath the fuel tank, and turn on the ign switch -- whereupon the gauge should read E.

Short together the blk/y and w/y leads on gauge side of 2-pin connector, whereupon gauge should read F.

If interested, the FSM goes on with more details about ohm readings involved for testing the sender and gauge and associated wiring.

Good luck!

Post edited by: Patton, at: 2007/12/16 01:31

thanx for the quick response!

I guess I wasn't very clear about what I have and need:

D2 in 1979 was a KZ1000 and a KZ650sr? I'm new to this stuff so I assumed (I know what to expect from that) that the D2 was specific to the 650sr--- my fault!

the sensor in question on the 650sr is a stationary unit that serves only as a trigger for a "low fuel" light. It doesn't have a variable resistor or float on it for a gauge.

is there anyone who can "clue me in" to how this simple little thing is supposed to operate? I don't even care that much if it works anymore, but it's driving me nuts that I can't figure out something this simple!

shortyyyyyy wrote:

the sensor in question on the 650sr is a stationary unit that serves only as a trigger for a "low fuel" light. It doesn't have a variable resistor or float on it for a gauge.

Sounds like the one on my 750. I'd love to know how the thing works too. Mine is broken as well.