Caliper Mounts on 79 KZ650 Fork?

I have a 1979 KZ650. The original fork resisted initial bumps and leaked, so I bought a left and right set off ebay which were also supposed to be off a 1979.

My wire wheel could accomidate a second rotor so I got one of those too and added it to the wheel, along with another master cyl and two caliper setup. Nice upgrade eh?

Here is the problem. All three calipers (1 old, 2 new)appear exactly the same. The new and old forks also appear exactly the same except caliper mount holes on the new forks are about 3/16 LOWER than the original. I have not found any other difference whatsoever.

Because the calipers are lower, the wheel is about 1/8" away from being fully seated.

Does anyone have an idea what is wrong? Could the new fork be off another year bike? It doesn't seem like there would be a rotor that is 3/16 smaller than the one I have.

I can attach images if it would help.

Welcome to KZr Clifford.

More than likely the forks you purchased on eBay are from a diff model KZ650.
There were three different KZ650 models in '79::
The KZ650B: (spoke wheels, single disc front brake and drun rear brake).
The KZ650C: Identical in overall apperance to the B model, but has dual front disc brakes, disc rear brake, and cast mag wheels.
The KZ650D (SR): similar to the C model in that it has dual front/single rear disc brakes and cast mag wheels, but the bodywork is entirely different, it has a 16" rear wheel as opposed to the 18" rear wheel like the C model, and it also lacks the "duck bill" rear painted fender like the B and C models have.

Here are the lower fork tube part numbers as per model in '79....
KZ650B: L/H 44005-1031 & R/H 44006-1031
KZ650C: L/H 44005-1034 & R/H 44006-1034
KZ650D (SR): L/H 44005-1012 & R/H 44006-1012

Post edited by: RetroRiceRocketRider, at: 2006/05/11 22:21

Thanks for the welcome! Nice forum. Wish I had started here when I started my restoration.

Thank you also for the part numbers. Any chance I can tell which parts I have?

There is no question my bike is a B model; Spoke wheels and single front disc. I noticed that on the right side of the wheel was a cover, under which were bolt holes for a disc. And my old fork had mounts for calipers on the right side so why not make it dual disc? I figured, incorrectly I guess, that another fork from the same year would work.

If I am understanding you correctly the difference between the B and C or D forks would be that the caliper holes are lower by a fraction of an inch? Does the C or D have smaller rotors or smaller front wheels?

Welcome. The B,C and D all have 19" front wheels, but as you see and have found, some parts are still different. You can check parts diagrams here: diagrams .
Press on continue after motorcycles, then chose the year, CC then All and All then continue. Next you can then chose the model then view parts diagrams.
Compare diagrams and numbers. Some parts will have different numbers between models, but can still work, others may not work.

Others have put dual disks on their B models, so it's do-able.

That's perfect.

I will post my next two questions as a new topic since thanks to you guys I know what I am looking for.

heres what left and right calipers look like side by side..i just did mine...steve

Post edited by: fixer5000, at: 2006/05/12 16:55

fixer5000 wrote:

heres what left and right calipers look like side by side..i just did mine...steve

<br><br>Post edited by: fixer5000, at: 2006/05/12 16:55

Yep, those match my calipers too.