TOPIC:

Diameter wise it looks like it may fit, although recessed. But the trim ring bends over a lip in the oem plastic housing. Trying to use the upper housing would require removing that housing, and the lip the trim ring needs to grab.

I call it the "pan fried aftermarket speedo" look!

I got my seat back from the upholstery shop. Letting it sit in the sun to relax the material and get some wrinkling out. I used the seat cover that Z1 Enterprises sells.

I am still waiting for the new POR15 chemicals to arrive for the fuel tank. I ordered them two weeks ago, but apparently the delivery has been slowed by the pandemic. Latest update is April 23. In the mean time I plan on working on the electrical system and start to tear apart the bottom end of the motor. Social distancing in my shop...

I am looking for the o-rings for the fuel tank, and Partzilla does not have a diagram for the fuel tank. It doesn't look like they offer the oval o-ring for the low fuel switch, only the oval petcock o-ring. Does anyone have a part number for that o-ring? If it can't be found, I could always make a block off plate and eliminate it. At this point I am not even sure if it works anyway. Finding the o-ring would be less effort than trying to make a block off plate, even if it no longer functions. Any way of testing it outside of the tank for functionality? Thanks in advance...

An odinary O-ring (Viton) can be formed to the same shape you need to seal your petcock. A Little smear of liquid sealant will support the positioning.

The part number for the fuel sensor o-ring is 430581004. This is from the 750H on cms (www.cmsnl.com/kawasaki-kz750h1-1980-usa-...37.html#.Xot8Em5uLic).
The E1 and E2 don't have a sensor according to the parts list - is it definitely the original tank?

Yes, it'sthe original tank.
The bike was given to me by the original owner. Tag says E1, but it's a 1981 - which is when the E2's came out.
Must be a late E1.

OK, probably the original tank then
That frame number is from an E2. They started at JKAKZDE14BA013722. Not sure when they finished as my model identification pdf only covers 79-81. The E1's had frame numbers KZ750E-000001 - KZ750E-012000.
Having said all that, the fuel sensor is the same as the one in my 750H1, so the part number I posted should be fine. I have an OEM o-ring lying around if you want me to measure it. It isn't shaped like the petcock ring so you can just grab a nitrile o-ring out of the box.

As noted by the frame numbers, I would expect a March build date to be in the middle of the 1981 production run, as they typically run August to August.

The 1981 KZ750-E2 wiring diagram in the shop manual I purchased online shows the low fuel sensor, but the sticker on the frame head says E1. They must have been using up the old run of stickers at this point in the serial number run.