KZ750H Restoration

Great job ob the gauges!

Super nice!!!

Got the front end done today. Finished off the wiring in the headlight so the electrics are done (except for replacing the connector on the low fuel sensor.







Got the front seat on as well. Even looks pretty tidy under the seat

Great job, except for the white dust speck on the tach. LoL

I've found a couple of other things to obsess over in the meantime

Got the switch blocks back together. Had them on the bike but was being so careful not to chip the paint that I squashed two wires (one on each side) with the plates that are used to hold them in place. Was wondering why fuses kept blowing :pinch:
Ended up getting the soldering iron out to detach the two wires so I could slip some heat shrink over them - not resorting to insulation tape yet!
All back together minus the plate holding the lighting wires in place as it doesn't seem to fit right on the new housing. The housing is from a German model without the reserve lighting device so two less wires running to the hi/lo beam switch. Will still be OK, just have to be a bit more careful when putting them on.

Nice job

Cleaned up the low fuel sensor today but before I repaired the wiring I decided to check that it was working. I figured if it was upright and not immersed in fuel then there should be continuity between the two connectors. No luck, no continuity (not even from the inside and outside of the sensor itself, so not a wiring problem). I'm not sure how these things work. If they're mechanical (with a float inside the sensor cylinder) then it may just be stuck due to the old petrol drying out and sticking (it hasn't been in gas for about a year). I'm soaking it in petrol at the moment to see if that sorts it out (although I'm not sure whether I need something stronger).
Problem is, the negative lead had broken off when I got the bike so I'm not sure whether it ever worked. Any ideas?

I think, if it's a low-fuel warning lamp, the sensor is a solid state device, rather than a mechanical float. If I recall, Martin_CSR has experience repairing or replacing those sensors. Maybe he'll chime in.

It's most likely a thermistor.

Thanks, it is the low fuel warning lamp sensor. I figured it would be too small to be mechanical - may have to start looking for a replacement... unless Martin has a miracle cure!

I've never dealt with one on a Kz, but I have replaced them on cars.

I'm looking at an 82 Kz750H2 diagram...
This diagram shows a green wire, but I think it might actually be a green/white wire.

One test you can do is to ground the green or green/white wire that goes to the sensor. The light should then go on.
If it does, then you prob have to get a new sensor.

You might be able to swap in a generic car thermistor if you think you can solder a new one in place. The one on my old car was a small "tank" just soldered to the stalk. The tank had a wire coming out. That would go to your green/white wire. The "stalk" is ground and is what the ground wire would go to.

They come in different resistance values and I couldn't find it in the cheap third party manual I have for 750's. But they usually come available in ranges like 50 ohms, or 100 ohms, or 1000 (1K) ohms. I guess I would try a 100 or 50.

When the fuel drops below the sensor, a small current through the bulb slowly heats the sensor and drops its resistance, which then allows more current and the light bulb to light up.

Be aware, this is mostly speculation on my part. So if someone more specific info, I would go with that.

Amazing resto, by the way!

loudhvx wrote: When the fuel drops below the sensor, a small current through the bulb slowly heats the sensor and drops its resistance, which then allows more current and the light bulb to light up.

Ahhh... that's my problem - I'm checking for continuity but there is no power to the sensor. I figured if it was disconnected the circuit would be closed if it's not submersed - a result of not understanding what is going on I'll fix the wiring and take it over to the shop to test it (the ground wire has broken off). Thanks!

loudhvx wrote: Amazing resto, by the way!

Thanks