Brake disc diameter on 77 KZ1000B

I Have a 1977 KZ1000A with dual discs (not sure if original duals or not). The front fender bolt hole has been broke off the left fork. I bought a set of good looking forks from a 1977 LTD off ebay. I replaced the seals, dust boots and oil. I installed the forks and calipers, went to put on the wheel, and it would NOT go on. The discs hit the top of the calipers.

I measured and the caliper mounting bolts are lower on the LTD forks. Measured center to center between the axle and the lower caliper mounting bolt holes it is 3 and 1/8 inch in the forks that are on my bike and the forks off ebay are 1/4 inch shorter and measures 2 and 7/8 inch. My bike has the 11 and 5/8inch discs (296mm I believe) and they do not fit on the new fork.

The forks from ebay are marked with K723R and K723L and they both have a "7" in a circle under the other marking.

I thought the only difference in the LTD discs in 77 was the thickness of the disc on the twin disc setup, not the diameter. Am I wrong? Did the 77 LTD use a smaller diameter disc? Or was I sold the wrong item off ebay?

Obviously the new forks won't work for me, I want to make sure when I sell them I am selling the correct item. Or if they are not actually 77 LTD forks I would like to find proof so I can return them for a full refund.

Thanks for the help!

PS-I am trying and will have a picture of my bike up as soon as possible

Bet you have a set of KZ650 fork legs. They use the same diameter fork tubes and seals as the KZ1000.

The triple trees have the same distance between tubes, but the KZ650 trees have less trail than the KZ1000 trees.

Only thing really different is the KZ650 uses smaller diameter front disc's than the KZ1000's.

So that means the caliper mounting bosses are closer to the center of the front axle than the KZ1000 forks!!!

The A1 did not have dual brakes - you have a wheel from something else on there. A 650 is a good guess.

So everyone agrees the forks I bought from ebay are NOT form a 77 KZ1000B LTD.
And averyone agrees the the A and B models should use the same diameter rotors. (Please correct me if anyone believes these assumptions to be wrong)

If they are from a 650 this would also explain the internal differences from the parts diagram when I was rebuilding them. There was an extra washer with holes drilled in it that slides on the bottom of the damper that was not on the 77 LTD parts diagram. I also forgot to mention the fact they are 1 inch shorter overall with shorter springs on the inside.

So for a solution, would it be easier to get 650 discs or find and rebuild a new set of forks? Would the 1inch shorter make a difference? Does anyone know what years/models of the 650 used the smaller diameter discs?

If not yet aware, there's lots of good info to be found on kawasaki.com, including parts diagrams, part names, part numbers, models sharing same part, availability, etc. Here's a link for help with navigating the site and finding information.

www.kzrider.com/forum/13-bike-related/37...imitstart=0&start=20

Good Fortune!

Here is a list of all of the bikes that use the 77 KZ1000B (LTD) front fork tube:

KZ650-B1 FRONT FORK
KZ650-B2 FRONT FORK
KZ750-B1 FRONT FORK (KZ750-B3-B4)
KZ750-B2 FRONT FORK (KZ750-B3-B4)
KZ1000-A1 KZ1000 FRONT FORK (KZ1000-A2-A2A)
KZ1000-B1 KZ1000 LTD FRONT FORK ('77-'78 B1-B2)
KZ1000-B1 KZ1000 LTD FRONT FORK ('79-'80 B3-B4)
KZ1000-A2 KZ1000 FRONT FORK (KZ1000-A2-A2A)
KZ1000-A2A KZ1000 FRONT FORK (KZ1000-A2-A2A)
KZ1000-B2 KZ1000 LTD FRONT FORK ('77-'78 B1-B2)
KZ1000-B2 KZ1000 LTD FRONT FORK ('79-'80 B3-B4)
KZ650-B2A FRONT FORK
KZ750-B3 FRONT FORK (KZ750-B3-B4)
KZ1000-A3 KZ1000 FRONT FORK (KZ1000-A2-A2A)
KZ1000-A3A KZ1000 FRONT FORK (KZ1000-A2-A2A)
KZ1000-B3 KZ1000 LTD FRONT FORK ('77-'78 B1-B2)
KZ1000-B3 KZ1000 LTD FRONT FORK ('79-'80 B3-B4)
KZ650-B3 FRONT FORK
KZ750-B4 FRONT FORK (KZ750-B3-B4)
KZ1000-A4 KZ1000 FRONT FORK (KZ1000-A2-A2A)
KZ1000-B4 LTD FRONT FORK ('77-'78 B1-B2)
KZ1000-B4 LTD FRONT FORK ('79-'80 B3-B4)
KZ1000-G1 Classic FRONT FORK
KZ650-F1 FRONT FORK
KZ750-G1 LTD II FRONT FORK

1976 KZ750-B1 FRONT FORK (KZ750-B3-B4)
1977 KZ1000-A1 KZ1000 FRONT FORK (KZ1000-A2-A2A)
1977 KZ1000-B1 KZ1000 LTD FRONT FORK ('77-'78 B1-B2)
1977 KZ1000-B1 KZ1000 LTD FRONT FORK ('79-'80 B3-B4)
1977 KZ650-B1 FRONT FORK
1977 KZ750-B2 FRONT FORK (KZ750-B3-B4)
1978 KZ1000-A2 KZ1000 FRONT FORK (KZ1000-A2-A2A)
1978 KZ1000-A2A KZ1000 FRONT FORK (KZ1000-A2-A2A)
1978 KZ1000-B2 KZ1000 LTD FRONT FORK ('77-'78 B1-B2)
1978 KZ1000-B2 KZ1000 LTD FRONT FORK ('79-'80 B3-B4)
1978 KZ650-B2 FRONT FORK
1978 KZ650-B2A FRONT FORK
1978 KZ750-B3 FRONT FORK (KZ750-B3-B4)
1979 KZ1000-A3 KZ1000 FRONT FORK (KZ1000-A2-A2A)
1979 KZ1000-A3A KZ1000 FRONT FORK (KZ1000-A2-A2A)
1979 KZ1000-B3 KZ1000 LTD FRONT FORK ('77-'78 B1-B2)
1979 KZ1000-B3 KZ1000 LTD FRONT FORK ('79-'80 B3-B4)
1979 KZ650-B3 FRONT FORK
1979 KZ750-B4 FRONT FORK (KZ750-B3-B4)
1980 KZ1000-A4 KZ1000 FRONT FORK (KZ1000-A2-A2A)
1980 KZ1000-B4 LTD FRONT FORK ('77-'78 B1-B2)
1980 KZ1000-B4 LTD FRONT FORK ('79-'80 B3-B4)
1980 KZ1000-G1 Classic FRONT FORK
1980 KZ650-F1 FRONT FORK
1980 KZ750-G1 LTD II FRONT FORK

So clearly, the problem isn't in the forks. All of these lower tube cover the bulk of the bikes built during that period.

One of the other forums asked a similar question about five years ago and came to no consensus. The best guesses were that the K723(L/R) forks were off a Honda or an older ('74) 650.

I have been reading other forums regarding the KZ650 to try and figure this out.

The KZ650 C and D models appear to be the ones which use smaller diameter rotors. The 650 C and D are also not listed on the above list of fork tubes (a very helpful list, thank you). I am starting to think the forks I bought are form a 650 C or D. However, according to Kawasaki.com the C and D used different fork tube lowers and I'm not sure which one I have. They look the same on the diagram, maybe one was painted different or had some other cosmetic difference. They use the same part number for brake rotor/disc which is not compatible with anything else.
KZ650-C1 (Custom) (1977)
KZ650-C2 (Custom) (1978)
KZ650-C3 (Custom) (1979)
KZ650-D1 (SR) (1978)
KZ650-D1A (SR) (1978)
KZ650-D2 (SR) (1979)

So I think I'll try to return them to the ebay seller on the premise that the item was not as described. If the return is unsuccessful I'll either try to find used rotors from the listed bikes above or find someone who wants to buy a rebuilt set of polished forks for a KZ650 C or D.

To the seller's defense - they might have been installed on a KZ1000 when he took them off without realizing they were from a different bike. As my daddy used to say: "Never ascribe to malice what you can explain with stupidity."

That list is wrong. And Kawasaki produced a kit to convert the 1000 to dual disk brakes.

750B1 and 750B2 forks are shorter than 1000 forks, and the fender mount is different.
76-80 KZ650 forks are 1" shorter than 1000 and 750B3/B4 forks.

And I know 650D rotors are smaller diameter than 1000 rotors, as I have a set off a 79 650D

Personal knowledge on the length and brake rotors. I have a stack of brake rotors, KZ1000 single disk, KZ750E dual disk, KZ750B single disk, 83-85 GPz750 dual disk, ZX11 dual disk, and probably a few more that I have forgotten. My 77 KZ1000A1 had dual disk brakes in 1979, because I installed them.

I assume you got that list from the parts diagrams at kawasaki.com? If so, you have just discovered that it is not always correct, a problem that's bit more than one of us in the butt..

I did not mean to imply he listed the item erroneously on purpose. I am sure the forks did come off of a 77kz1000B. However this does not change the fact that what I got was not the forks from a 1977 KZ1000B. I plan on being as polite as possible as this is usually the best way to come to a mutually beneficial outcome.

Even if he gives me a full refund he still wins because I will be returning forks with brand new seals.

steell wrote: ... Personal knowledge on the length and brake rotors. I have a stack of brake rotors, KZ1000 single disk, KZ750E dual disk, KZ750B single disk, 83-85 GPz750 dual disk, ZX11 dual disk, and probably a few more that I have forgotten. My 77 KZ1000A1 had dual disk brakes in 1979, because I installed them.

You win - you are clearly smarter than me. I am humbled in the presence of a master. I was just trying to help - I'll shut up now.

Cynjut wrote:

steell wrote: ... Personal knowledge on the length and brake rotors. I have a stack of brake rotors, KZ1000 single disk, KZ750E dual disk, KZ750B single disk, 83-85 GPz750 dual disk, ZX11 dual disk, and probably a few more that I have forgotten. My 77 KZ1000A1 had dual disk brakes in 1979, because I installed them.

You win - you are clearly smarter than me. I am humbled in the presence of a master. I was just trying to help - I'll shut up now.

Well, if it hurts you to be told the kawasaki.com parts diagrams are often wrong, then tough, go complain to kawasaki. If it hurts you to be told about the dual disk brake kit, then see above.

No one knows everything, no one is right 100% of the time, so grow up.