TOPIC:

I was aware of the 78 Z1R and 78 Kz650-SR using the 38mm piston, but I'm not sure about the KZ1000A2. The Z1R and SR are both dual caliper, but the KZ1000A2 was still single, wasn't it? It seems like all of the single caliper bikes used the larger piston. Maybe the '78 KZ1000B2 and the '78 KZ1000-C1 (police) had the smaller piston, as those would have been dual disk?

I had the impression that the 38mm piston was only used on 1978 model years. That came from looking for parts when Kawasaki provided access to their full parts database, which had accurate part number info, would show obsolete and superseded parts, and allow one to cross reference a part with all models where it appeared.

The current on-line catalogs (partzilla) show the 38mm on 77 and 79 models, but I don't really trust the new databases.

It still drives me crazy that Kawasaki took down their real dealer quality pars catalog. All of the third party parts catalogs available now are no longer accurate (partzilla, etc.), and Kawasaki no longer has any way to cross reference parts. It sucks.

That's Clean! Baldy. Nice and clean and smooth! Like a fresh waxed *****
Got some similar ideas on parts. I sold a project on ebay last year. Only went up to $88 bucks.
Then I machined 2 - 7mm rotors after drilling the together! Like an idiot rookie! I never flipped 1 -180 degrees for other side! So the pattern is same. if used together one side is running backwards. So they are selling as 1 rotor for a KZ900 single.
h well, live and learn! []

Mikaw got you covered on the RH Caliper Holder. It's the smooth plate as "I think" most RH holders were all smooth Not dimpled. I HOPE the KZ900 caliper you purchased has a nice packing seal land and piston/casting land isn't all pitted-up. The correct period piston is 43048-006 for the KZ900 for reference and it's a 43mm, photo provided. Let me know what else you need after you get the caliper. As mentioned you can use a smear of silicone grease on back of pad to piston. I personally like Dow Corning High Vacuum Grease? Just make sure it's NOT petroleum based, petroleum based will leech into the pad material.

Mikaw wrote: Baldy110, are those NOS rotors or did you have them resurfaced? I looked locally here to find someone that could resurface the rear rotor on my '78 1000 B2 without any success. It squealed and I want to resurface it. Not have any luck I just put in new pads, but its already making noise. any recommendations?

The squealing usually comes from between the back of the pad and caliper. They sell an adhesive specifically for this, or you can trim a set of pad shims from a car to fit.

I believe the OEM pad on piston side came with a shim, aftermarket pads were a mixed bag, some did some didn't. I suppose the reason factory went with the caliper piston with the phenolic insert starting sometime in 78-79.

Asphalt900, thank you. There is a place here in Michigan I found that sell old Kaw parts. It’s about an hour ride but worth it. I can go there and pick out what I need and get the pick of the litter so to say. I will run up there in the next few days. I will take a digital caliper with me. Maybe over thinking this but, is it correct to have the smooth and dimpled caliper bracket on the same bike.

As for the squeal. I know when I redid the fork seal and installed new brake pads I noticed they had a metal shim riveted to the pad, it was a D shape that only covered half the pad. I checked the FSM and orrintated them correctly before install. As for the rear I don’t recall if the pad had the sim. Now that Baldy110 helped me with the rotor resurface source, I’m gonna pull the the rotors off and ship the out. Good winter project while I collect the 900A4 parts. The new pads have less than 200 miles on them so I hope they are still reusable.

I have both calipers disassembled. One cleaned up with some brake clean and the parts washer, the other was repainted by the PO. I soaked it in the parts washer fluid over night and that cleaned out all of the left over gunk, but it didn't touch the paint or the corrosion in the piston seal recess. It spent the night in the carb dip and that allowed me to scrub off the layer of paint but it didn't get all on the corrosion. In the past I've hade good luck soaking carb bodies in CLR, seeing how the caliper is aluminum I'm assuming it would be ok to soak it in CLR to get the last of the corrosion off.

Any one have a comment on soaking the caliper in CLR???

I just read this


Posted by
Lynn Sorrell
on Jan 28, 2019

What will CLR do to copper or aluminum?

CLR will take the finish off of aluminum and copper.


What surfaces should I not use CLR on?

Quote; DO not use CLR on natural stone or marble, terrazzo, colored grout, painted or metallic glazed surfaces, plastic laminates, Formica, aluminum, steam irons, leaded crystal, refinished tubs or any damaged or cracked surface. CLR may etch older sinks, tubs and tiles. CLR is corrosive. Avoid contact with wood, clothing, wallpaper and carpeting. Some laminated surfaces (counter tops) are coated with a synthetic surface which may be affected by rust removers; clean spills immediately. CLR website www.thecarycompany.com/facility-supplies/cleaners/clr/faq Use Brillo pads
End quote )



Simple green is similar " I think " and I will use that stuff to clean external engine parts or bare metal and then neutralize it with soapy warm water and a good rinse,
At that point it needs to be protected from oxidation.

but I don't use it for the insides of anything.

I like this stuff because it is ( . Non-corrosive to common metals under normal exposure time )
and it works on ( acrylics, lacquers, polyurethanes, baked enamels and epoxies.)
It can be found in auto parts stores
Soapy water and a good rinse for this stuff too.
Also wear gloves



Professionals rely on Aircraft® Paint Remover to quickly and effectively remove a wide range of finishes from the metal surfaces of automobiles, trucks and cycles — including acrylics, lacquers, polyurethanes, baked enamels and epoxies. Non-corrosive to common metals under normal exposure time. The fast acting formula starts working in just five minutes, goes on thick so it’s effective on vertical surfaces, and cleans up with water.

Thank you bluejay58. I’m not worried about the paint, that will be removed at the powder coat. I’m trying to get the rust out of the bridge pipe and bleeder area.


And a little bit of corrosion and rut out of the piston bore. I’m hoping this is just surface rust and it will come off during a short soak in CLR. I have soaked carb bodies in it with great success.

The rust is from the banjo bolt and bleeder screw and held in place by dried out Dot 3
Fresh brake fluid will soften it, so will aircraft paint stripper,
CLR will attack the aluminum , make sure and wash it good afterwards.

I would try a small diameter wire brush, set up on a circular drill for the bridge pipe. I would run a tap down the bleeder hole. For the piston bore....a very fine sandpaper...say 5000 grit or more.

Thank you for the advise... Ill soak it in brake fluid, while I hit HF for some small rotary wire brushes.

Just landed a matching set of 0T-October/November 1975 rotors. I have also ordered new hoses, RH and LH bridge pipes, and Hose brackets, all new, I have in my old parts bins a double splitter and found a RH caliper with bracket at Z-Fever... Im sure I have a 5/8 MC here just have to dig it up and rebuild... it almost all together.

Question for the experts. What dust shields do I need to convert the front hub to dual disc. Are the axle spacers the same???