Kz550 wheel rotor?

Ok so I have a 1980 kz440 that I'm doing a lot with, one of those things is to convert it to disk brake in rear. Now I already have a wheel that fits close enough to space to fit it's a 1983 kz550 16" rear wheel. This is all I know about the wheel. It did not come with the rotor or sprocket assembly. I have acquired the sprocket assembly but now I need a rear rotor and caliper to proceed with the swing arm modification. I can not find a rotor for this wheel. I have called local stores and they say that they don't list a rear rotor for that year make model. It has a 4 bolt pattern for the rotor and is about 3" diameter from outside bolt hole edge to opposite edge. I just need something that will fit this pattern and I can get a matching caliper.

Does anyone have any clues for me as I have been googling for days on this?

There was no 1983 KZ550 model with a 16" rear wheel that used a disk brake. The only 1983 KZ550 that came with a rear disk brake was the GPZ, but it used an 18" wheel. If you are going to find the parts you need you must first correctly identify the wheel. Ed

The seller I bought the wheel from double checked and said it was indeed a 1983 kz550
I tried google images 1983 kz550 ltd there are pictures and spec sites that mention the 550 ltd having a rear disk brake, but that's why I'm posting is because I am so confused. Maybe it's like a certain one that had the disk brake?

If you check Kawasaki.com or Partzilla, they will show that the 550C Ltd had a Rr drum brake.
The 750H Ltd had a rear disk brake, but I have no idea how much work it would be to make it fit a 440. I'd guess the swing arm & frame are wider on the 750. It could be that the google pics you're finding are of modified bikes or you're assuming they're 550s without investigating the hits carefully enough. A photo of your wheel might help. or a link.

chris_heiges wrote: The seller I bought the wheel from double checked and said it was indeed a 1983 kz550
I tried google images 1983 kz550 ltd there are pictures and spec sites that mention the 550 ltd having a rear disk brake, but that's why I'm posting is because I am so confused. Maybe it's like a certain one that had the disk brake?

Look at the links below and tell me which one has a disk brake in the rear. Then PLEASE send me the link that shows a disk brake on the rear of a 1983 KZ550 other than the GPZ which has an 18" rear wheel. I would love to see it! Either your seller is wrong or else someone had put a different wheel on the KZ550 he had and he didn't know it.

www.powersportswarehouse.com/p/Kawasaki#...50-A4-1983/080121L-5

www.powersportswarehouse.com/p/Kawasaki#...50-A4-1983/080121L-5

www.powersportswarehouse.com/p/Kawasaki#...50-M1-1983/080152F-5

www.powersportswarehouse.com/p/Kawasaki#...0-F1-1983/080151E-13

Here's what I found that has me confused.
Here's a copy and pasted section from the link I'm going to try to put below the pasted section.
"This was the first of the line, with a 500cc DOHC engine, later bored out to 553cc's and also available as the 398cc Z400J (identical to the Z550). Early Z550 models (1980-1981) had a double disk brake in the front (The US model KZ550 had a single disc brake) and a drum brake in the rear, with a conventional swingarm using twin shock absorbers. Later models (1982-1983) had improved brakes (twin discs in the front, with a single disc in the rear). The original Z500 (1979-1980) differed from the early Z400/Z550 models in having twin front and single rear discs"

www.classic-japanese-bikes.com/Kawasaki-KZ550.html

I could be wrong or reading it the wrong way, I mean it doesn't say that it was a ltd version that had a rear disk brake they could just be referring to the gpz. That website could be wrong too. Also the seller could be lying to me and I have asked them to check again one more time, but in the mean time I have a wheel that has a 130/90-16 tire on it that I just received a 83 kz550 sprocket and Cush drive that fit and it fits in my kz440 swing arm and is almost lined up sprocket wise. I just need a rotor for that wheel and a caliper for that rotor. Does anyone have any suggestions as to a model that had a 16" wheel with a 4 bolt rear rotor?

A factor not mentioned yet is where a model was sold. The beginning of that article references the Z500 w triple disks which was not sold in the USA. it probably had an 18" Rr wheel.

I think you are misreading that article. When they say rear discs were added, they are referring to the Gpz, as Ed mentioned. And as Martin mentioned, it would help if you can confirm you are in the U.S., as that will narrow down the model choices for discussion, as it's more difficult to find parts listings for European/Asian/SouthAm/Aus bikes.

EDIT: Ok, I see you're in Virginia.

If you are in the U.S., the only rear disc 550 for 83 is the Gpz model, and you will know it immediately since it only has 5 spokes instead of the usual 7, and it originally came only in red. The 81 gpz 550 had 7 black spokes. The discs are held on by the same number of allen bolts as the number of spokes.

If it's held on by four bolts, it would have to be from a different size bike, or from a different year 550, or some home-made modification.

81 gpz had 7 spokes and 7 bolts.
82-83 had 5 spokes and 5 bolts.
The later gpz's had 6 spokes and 6 bolts.

I'm trying to upload a picture of the wheel.
Let's just assume they lied to me
And I see I clearly read the article wrong.
So I need your help to determine what year and model this wheel came off of. It has 7 spokes and accepts the 83 kz550 sprocket and Cush drive I just got used. But on the rotor side it only has 4 bolts???

I'll take some pics of the wheel when I get home that's all I had at the moment

Ok, then we will need a little more info:

Does it say the word "tubeless" anywhere cast into the spokes or rim?

Is there a tire on it? If not, post a pic of the inside profile of the rim.

Are there rim-locks on the rim? They look like places where the stem might poke out, but there will be a nut and bolt there instead. Take a photo of that if they exist. Actually post a pic of the entire wheel if you can.

This will help to narrow down if it's from the tube era, or from the tubeless era.
And maybe even an aftermarket rim.

(Personally, my money is on a Kz650sr rim... any takers?)

I'll get some detailed pics when I get home but I think that I remember seeing Kawasaki on the rim, it has a tire on it, I don't believe that it's tubeless and there were no lock things on it like described. Of course I could be wrong but like I said I'll get better pics tonight