What rotor will work with 1981 KZ650 H1??

Ok guys, I have been restoring my 1981 KZ650 H1 for a while now - its been down for about 3 years - I just got the carbs done and I am currently working on a valve adjustment and I thought I would check out the front breaks as I am nearing completion finally. Well guess what my front rotor is only 4.2mm thick which is below the service limit of 4.5mm Normally this would be fine I would just find a new rotor and purchase it, except every dealer I have called said I can only get an OEM rotor which is from $280-$370 :ohmy:

So here is my question, does anyone know if I can use a rotor from another year/model that will fit my bike? Can I get a new aftermarket one that doesn’t break the bank?

Welcome to KZr jeffo.

Unfortunately, the part number for your bikes front rotor (41080-1037) shows as only fitting your bike in the Kawi x-reference software. :pinch:

There might be a rotor from another year 650, or diff model KZ altogether that will be a direct bolt-on. About the only way of knowing which will fit is to have someone that's already done this, or trying various rotors until you find what will work.


Sorry I couldn't be of any real help.

Thanks RetroRiceRocketRider!

I am kind of hoping that someone on this forum has done this before and would know of a different year/model that would be a direct bolt on? :huh: We will just have to see.

Otherwise I may have no choice and dish up $270 for a new one :sick: :sick: :sick:

Post edited by: jeffo, at: 2007/07/09 04:38

I know this post is really old but did you ever figure anything out for a rotor? I need one for the exact same bike. I wonder if swapping wheels would work? That might be my only option at this point since there aren’t anymore new discs available for this bike. Maybe it’s time to put a modern fork on this old bike. Sad thing is, my bike only has 12,000 miles.

KZFreak wrote: I know this post is really old but did you ever figure anything out for a rotor? I need one for the exact same bike. I wonder if swapping wheels would work? That might be my only option at this point since there aren’t anymore new discs available for this bike. Maybe it’s time to put a modern fork on this old bike. Sad thing is, my bike only has 12,000 miles.

What's wrong with the rotors you have? Are they worn thin?

EBC MD4065LS is listed as a replacement. Catalog available on the EBC website.
www.amazon.com/EBC-Brakes-MD4065LS-Brake-Rotor/dp/B0073DWVAO

The 6-bolt rotor listed in that Amazon link is probably for the 83 650-CSR w cast alloy wheels. The 1981 KZ650-CSR has a 4-bolt Fr brake disk, and from the cross-reference at partzilla the 650-H1 brake disk was only used on the 81-82 650-CSR & 82 750-CSR Twin.

If you can't find a stock-type rotor, you can install cast alloy wheels from a number of KZ models & those rotors should be more readily available. I installed the wheels from a KZ550C Ltd & they were a direct swap (credit to Andy-the-gringo) >> all I needed were the wheels & Fr brake disk. everything else swapped >> axles, speedo drive, brake panel assy, sprocket carrier, etc. Other wheels will fit, especially the front.

1981 KZ650-CSR w KZ550 Ltd wheels.

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I was just checking on partzilla.com The CSR 650 left side front hub dust cover is shared with these models below .81 1000CSR front disc. diameter is 270mm,81 305 CSR 255mm,82 750 twin CSR 250mm. Possibly one of these my work if diameter and offset is the same.

This Kawasaki 14025-1277 COVER,DUST,LH Not Available fits the following models and components:

Kawasaki Motorcycle 1982 CSR - KZ1000-M2 Front Hub

Kawasaki Motorcycle 1981 CSR - KZ1000-M1 Front Hub

Kawasaki Motorcycle 1982 CSR Twin - KZ750-M1 Front Hub

Kawasaki Motorcycle 1981 CSR - KZ305-A1 Front Hub

Kawasaki Motorcycle 1982 CSR Belt - KZ305-B1 Front Hub

Kawasaki Motorcycle 1982 CSR - KZ305-A2 Front Hub

Kawasaki Motorcycle 1983 CSR - KZ650-H3 FRONT HUB ('81-'82 H1/H2)

Kawasaki Motorcycle 1981 CSR - KZ650-H1 FRONT HUB ('81-'82 H1/H2)

Kawasaki Motorcycle 1982 CSR - KZ650-H2 FRONT HUB ('81-'82 H1/H2)

Kawasaki Motorcycle 1987 LTD - KZ305-B2 Front Wheel

Kawasaki Motorcycle 1988 LTD - KZ305-B3 Front Wheel

There are CSR 650 and 750 twin CSR rotors on ebay today.

martin_csr wrote: The 6-bolt rotor listed in that Amazon link is probably for the 83 650-CSR w cast alloy wheels. The 1981 KZ650-CSR has a 4-bolt Fr brake disk, and from the cross-reference at partzilla the 650-H1 brake disk was only used on the 81-82 650-CSR & 82 750-CSR Twin.

The EBC website states the rotor fits 81-83 650 CSR bikes. Beyond that I'm not sure.

It's pretty common for places to erroneously lump all of the 650-CSRs together. I usually see it in regards to the carburetors & airbox >> the 81 has VM24 carbs & unique ducts, while the 82-83 have BS32 carbs w 750-4 ducts. The disk for the 81-82 models w 48-spoke wheels is completely different than the disk for cast alloy wheels on the 83 CSR.

Edit: in the EBC catalog that 81-83 650-CSR rotor is listed as a floating rotor conversion, and I don't know what's involved to install it. probably not a direct bolt-on. Also, I didn't notice that the MD4065LS rotor has 5 bolt holes >> the 81-82 650-CSR have 4 & the 83 has 7.
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I found this chart and used it to find the rotor/pads for my 400.

jcmotors.com/SizingChart/ebc-brake-spreadsheet-1.html#tab4

My rotor is within wear limits but has grooves in it from the caliper leaking. I assume dirt and debris collected and caused the damage.. I bought a rotor from a 750 twin online and it is in decent shape but just a tad taller sitting next to mine on the bench. My stock rotor shows minimum thickness of 4.5mm. The rotor from the 750 twin shows 5.5mm. I have yet to try it as I am still looking for lower fork bushings, which are unavailable and not shown or listed on any schematic or parts diagram for my bike. Pyramid Parts in the UK claims they will have the bushings in three weeks and that they match my measurements (35.7mm o.d. X 33.7mm i.d. X 20mm), but we:ll see. If all else fails, I'll use two 10mm bushings side by side in place of the stock 20mm. I hate to have to improvise, seeing as how I just bought an NOS set of fork legs and don't really want to experiment with them. I guess I could try it on the old ones first. Thanks for your effort and input.