10 fiber/9metal clutch plates in a KZ1000?

I'm working on a 80 KZ1000D3 (Z1R). The manual and parts diagram show 8 fiber/7metal clutch plates. This one has 10 fiber and 9 metal plates. 2 of the metal plates are copper color with no dimples on the plate surface. The other 7 look like stock Kawasaki items (silver w/dimples).
I bag and label everything during disassembley, but should have payed better attention in this area. There's a spring in the clutch assembly bag that appear to fit over the clutch push rod against the clutch spring plate pusher. It's also not shown in any factory manuals/diagrams. The basket, hub and spring plate all appear to be stock.
Does this bike have some sort of aftermarket/upgrade clutch kit? I ordered 8 stock fiber plates based on the parts manual. Should I just use the 8/7 as shown, or order 2 more fiber plates?

Sounds like a redline or track king clutch, the plates are slightly thinner to fit more in. Good part, worth keeping.

Someone has fiddled around in there, I would replace both sets of clutch plates with the genuine parts. Ed
See:
www.powersportswarehouse.com/p/Kawasaki#...0-D3-1980/070081H-10

As above, hopefully you just have an extra plate performance clutch fitted and this will probably have been fitted to cope with the extra power produced due to other engine upgrades.
It's worth checking what spec the motor is before reverting back to stock.
In the extra plate kit the plain plates are the same thickness as stock but the frictions are thinner and the kit contains a full set of new frictions but only the extra plain needed to make up the numbers hence the mix of silver coloured stock and copper coloured aftermarket.
However the extra plate kits for the Z1R D3 have only one extra plain to make 8 metal and 9 friction.
If you really do have 9 metal and 10 friction then someone has squeezed in two extra of each plate which is not ok unless someone has fitted a later basket or machining to the clutch assembly or pressure plate has been done.
In stock form the fitting of 10 frictions will push the pressure plate too far out along the splines of the inner hub and when disengaged it will clear the end of the spines allowing the pressure plate to rotate independently to the inner hub and then when re-engaging the clutch there a chance that the pressure plate will sit on the ends on the splines and not re-engage and you will lose drive.
What will actually happen on re-engaging though is that the pressure plate will not simply be held off the clutch pack by sitting on the end of the hub but it will bounce on the end of the hub as it spins taking metal off both the hub and pressure plate splines shedding aluminium shavings in to the oil before eventually dropping back into its correct position.
The pressure plate will also rub on the inside of the clutch cover when disengaged producing more damage.
Hopefully you have either miss-counted the plates or the PO has known what he was doing and not just ignorantly squeezed in too many plates because it appeared there was enough room on the hub.

I've rebuilt the engine due to some water in cylinder #4. It is stock with no HP mods. I have met the PO and while he wasn't overly mechanical, he didn't hesitate spending money for professionals who were. I've got a stack of receipts an inch thick from shops around the country. He used the bike as sport tourer and said the bike had plenty of power just the way it came. All his efforts were in handling, comfort and reliability. The frame has been braced, and there's a $300 receipt from a frame shop in CA (Santa Anna I think). He claimed that was the shop that did all the Kawasaki superbikes for the factory team at the time, so that's where he sent it. $300 was a pretty good chunk of change back in 1980,
It definitely had 10/9 clutch plates. I counted multiple times because it didn't make sense. I'll measure and compare thickness of the fiber plates once the stock replacements arrive. These did seem thin, but I assumed it was just wear. I'll also inspect the rest of the clutch assembly and cover closer for any signs of modification or machine work.
Ever seen the spring on the spring plate pusher shaft before? I'm guessing it was there as an assist to make sure the spring plate fully opened to the additional space requirement of the extra plates. Maybe it made the clutch pull easier with heavier springs?

Some of the extra plate kits used thinner steels also . all depends on the make and some just include the extra steel needed whilst others include the full set.
What strength spring is behind the pusher ???
The spring behind the pusher mushroom would make sense if a roller pusher was being used and it would only need to be a very weak spring.
The spring would keep the radial bearing sandwiched between pusher and pressure plate when the clutch cable etc was changed or adjusted or the pushrod removed for any reason.
Excess slack in the pushrod can allow enough room for the radial bearing to drop into the clutch hub and a spring behind the pusher will prevent that.
Can't really see any other practical reason for having a spring there as the last thing you need ( if it's a strong spring ) is an opposing force acting on the clutch springs when they are trying to maintain grip and it would partially defeat the object of having heavier springs in the first place.

I do remember a kit in the late 70's and early 80's, that did use 10 fibers and 9 steels, but don't remember who, believe I even tried it, Barnett comes to mind but could be wrong ( getting old ). The plates were so thin that they broke really easily.

don

It's a lightweight spring. I had the same though that it would be basically a spring pushing against the clutch springs. It has to be just to maintain a level of tension in the clutch pushrod assembly. I'll have to give the pusher a closer inspection as well

I run a APE KZ1000 extra plate kit in my ZX750A1 motor
and gained one steel and two frictions and have two frictions left over.
Stack count is now the same as a stock KZ1000.

I spent many hours diagnosing ZX11 clutch problem. Clutch was slipping but everything seemed to be fine. Finally I realized that aluminum pressure plate was worn out. Solution was very simple: I just installed extra steel disk.
It doesn't really matter how many disks clutch has, summary thickness is important.