Closing in on first KZ, but have questions

I know most of you guys have a great deal of knowledge about these bikes, but I am searching for my first KZ. I’ve loved these since the 70s. If there are any “stickies” in the forum about bike model history, differences, feel free to point me there ( I searched; had trouble finding what I was looking for except for the thread on the two types of engines for KZ1000’s. I bought my first Kawasaki Enduro bike in 1975. I haven’t had a motorcycle since 1982 (when mine was stolen). Now that my sons are grown, I am itching to buy a motorcycle (my son has a new Yamaha Sport Bike), and while almost pulling the trigger on a newer Moto Guzzi, I have decided that I want an early 80’s KZ model.

I am pretty sure I’ve narrowed my search down to 1981 or 1982 KZ 1100 or 1000 models. I believe I’ve ruled out the LTD or Spectre models due to the higher looking front forks and more cruiser looks. I basically want a good running example, that’s been well maintained (or restored similarly), but doesn’t have to be concours...just fairly decent shape with a good tank.

So my questions are:
1) What differences are there in the 1100 vs 1000 cc engines? Any maintenance issues/differences between the two?
2) How much taller are the forks/riding position on the LTD models?
3) I’ve seen some logos on the side that say “KZ1100”, and some that say simply “Z1100”. Any differences in those bikes?

Again, I apologize for the newbie questions, but I did search multiple times trying to find answers on my own. Thanks for any comments or suggestions.

Thank You!
Steedracer
Brentwood, TN

Don't know much about the later bikes but KZ was the US designation and Z was ROW designation. Generally KZ's had minor mods such as shorter rear mudguards, some type of smog/pollution control, speedo's with lower MPH top limit, and more reflectors. Your American legistrators are more safety conscious.

Also, the shaft drive models have quite a few unique parts, some of which may be getting hard to find. All of the 1000/1100 bikes are well built and very reliable. As with any used machine, the most important matter for a buyer is how well the bike has been taken care of. A properly cared for KZ1000/1100 can easily pass 100,000 miles with no major repairs. On the other hand, a badly neglected and abused one can need major repair after a few thousand miles. Care and condition should weigh heavily in your decision.

Steedracer wrote: So my questions are:
1) What differences are there in the 1100 vs 1000 cc engines? Any maintenance issues/differences between the two?

There is a substantial difference between the 73-80 engines and the 81-84 engines. But it seems like you're focused on bikes from 81-84. All the bikes from 81-84 are the same general design, called he "J" engine. Within those years, the Kz1000 vs Kz1100 difference is mostly just the piston size. One big change is they improved the head design on the GPz1100 model, what's called a "Bathtub" head. Some other models got a variation of this revised head as well, but I don't know exactly which.

The only complaint I've heard of with the "J" is that some of the cranks are prone to twisting. I guess it was a tolerance issue. But I'm really more familiar with the 73-80 engines.

2) How much taller are the forks/riding position on the LTD models?

I think the forks are largely the same. The difference is in the bars and seat. The bars are definitely higher. It certainly puts your hands up higher. But the seat height for the driver is probably pretty similar.

Here is an overview of the "big four" Kawasaki Z bike. This covers the Z1 > KZ900 > KZ1000 > KZ1100 > GPz1100

From the highest level, you can split these up into two designs. The 1973 to 1980 bikes, and the 1981 to 1984 bikes. The Z1 was tweaked and refined until 1980. For 1981, nearly everything was redesigned. The frame, engine, brakes, etc are substantially different between the two groups.

The first group includes the Z1, Kz900, and Kz1000. The Kz1000 had several trim variants. The standard "A", the LTD (, the Z1-R (D), the Shaft (E), the Police (C), Classic (G). All of these years and models shared the same general frame design and engine design. Parts evolved over time, but they are more similar than different. The trim differences are largely cosmetic, primarily the handlebars, seat, fenders, tank, and exhaust, although there are some real mechanical differences between trims. The Shaft and the Classic are probably the most different mechanically.

As a rule, the engine is nearly identical across all trims for a given year. The engine was revised for 79-80, called the Mk2 engine. There were real changes to the head, crank, cases, etc., but the parts are nearly 100% swapable between Mk1 and Mk2 so it's still pretty much the same engine.

The second group is the 1981 to 1984 (but actually 2005 for the Police model). A clear division within this group would be the twin shock and mono-shock bikes. The GPz model for 83-84 had more power (better head), plastic fairings, the mono-shock, fuel injection, etc. The (non-GPz) twin shock models are more similar that different. Twin shock trims included the CSR, LTD, Spectre, Shaft, ELR (Eddy Lawson Replica), the standard "J" model, Police model.

The difference between the early 73-80 and 81- bikes is substantial. Nearly every part was re-engineered. The frame is all new and substantially stiffer, with new geometry. The engine is an evolution of the '73 design, but nearly ever part was redesigned. The new for 81 engine is typically called the "J" engine. They don't easily swap between frames, as the "J" has different mounts to add rubber isolation. Continuing with the changes, the brakes changed, the wheels changed (tubeless), the gauges changed (more like a dashboard), the carbs changed (constant velocity instead of round slides). Really nearly everything was revised.

Here is the model and trim evolution of Z1. The Z1 ran from 1973 to 1975. The Kz900 appeared in '76, but was nearly the same. The LTD sub-model appeared in '76. The Kz1000 appeared in 1977, along with the Police model. The Z1-R variant appeared for '78. The Mk2 engine appeared in '79, along with the Shaft model. The fuel injected Classic came in 1980.

I started a list of all of the detailed model changes from 1973 to 1980. I'll can add it if anyone wants. Someone else will need to do the >81 bikes, as those are not in my head.