TOPIC:

Looks like I am going to have to make a ground cable running from the battery to the chassis on this 81 GPz550. Has anyone done one before and could clue me in on where to get the wire, ends, etc?
Thanks

Chopper

Go to the auto store and get a cheapo set of car jump leads. Cut what you need from the black cable. Refit the Croc clip. 
Make up your bike ground lead. 
End up with a ground lead and a set of jump leads. 

For the cable ends.
These crimp kits are cheap and work well.
VEVOR Crimping Tool Battery Lug Crimper AWG10-1/0 Copper And Aluminum Terminal | eBay

I used prowire.com for wire and connectors.
A Harbor Freight hydraulic crimper for my battery cables. I had to crimp several power cables for my truck so the hydraulic crimper made sense.
For battery cable I use cable meant for motorsports. It's usually more durable and chemical resistant as well as more flexible due to the high strand count.
I used 6 awg for power and ground.


hydraulic crimper

battery cable terminals

battery cable  

 

Another option. Welders wire, very flexible for routing because the individual copper strands are much thinner and more of them compared to comparable wire one can find at an Auto Parts store in bulk behind the counter. And..it can carry amperage to suit.   

Nothing on EB?  you might be able to use one from a different model, maybe even from a modern motorcycle. 
I saw one from a Ninja 250 that might work. item #134797655347. or maybe #124913461890
The shape of the battery lug may matter for fitment's sake.

From the diagrams your battery terminal lug has the ground harness lead but you could get that separately if needed. the 650-CSR for example has an accessory ground that might could be used. KZ550 engine ground only #225516591139. you'd need an acc lead.

 

<<From the diagrams your battery terminal lug has the ground harness lead but you could get that separately if needed. >>

Could you please school me on what this means? My electronics juju very weak. I CAN however tell what size TK main jets are by sight.

TIA

Perhaps these

www.siriusconinc.com/products/detail/3804

No idea what size are the lug holes.

EBAY    2/ 1982 82 KAWASAKI GPZ550 GPZ 550 OEM NEGATIVE BATTERY CABLE GROUND WIRE | eBay
 

<<From the diagrams your battery terminal lug has the ground harness lead but you could get that separately if needed. >>

Could you please school me on what this means? My electronics juju very weak. I CAN however tell what size TK main jets are by sight.  

The parts diagram shows that your motorcycle has a fat grounding cable with smaller gauge wire at the negative battery terminal. see link.
#26011 in the diagram >> www.partzilla.com/catalog/kawasaki/motor...electrical-equipment

If you can't find a suitable replacement with the smaller gauge wire, you could get the fat ground cable then use an accessory ground like what's found on my motorcycle. Those ebayy item numbers provided should be helpful to see what I'm talking about. acc wire lead: item #331979771699

ps: the fat grounding cable goes from the negative battery terminal to the engine where it's bolted to the engine >> there should be a ring terminal on that end.