Questions about 81 kz1100

Hey guys, long time lurker first time poster. Long story short my dad gave me his 81 kz1100 shaftie he has had since I was a wee lad. Altho I prob wouldn't have bought one for myself I'm a big gear head and with a family of four I don't have money to play with 4 wheeled vehicles anymore lol. So I think this bike will make a good project bike for me, ride in the summer, wrench and customize during the winter. So my question is what exactly is different on the 1100s versus the popular 1000s. I've done a good bit of research but info on the 1100s seem much more difficult to find than the 1000s. Like what is bigger on the 1100s the bore, stroke, or both? Are all other parts interchangeable? From what I've found it seems the cam grinds are different. Oddly partzilla.com has the same part numbers listed for cranks and pistons. And while we're at it are there any differences in the frames?

I'm mainly trying to get an idea of what parts I can use on my 1100 that may be easier to find listed for a 1000, and partly just for curiosity's sake.

Appreciate it

The "J" engine...sweet.
Lots of parts available, both used and new. Be careful not to become a Kawasaki addict, but there's plenty of people here to help you, when (not if) you do. :lol:

Those are nice bikes. I only had a couple of beefs with them - first, the PC 85 mph speedo, which is an insult to a big Kawi - the other one is the way they tuned them to run lean and hot for Jimmy Carter emissions standards. If it were mine - I'd do a little work on the carbs, just to get it running nice and smooth, and not cold-blooded, and if it started using oil I'd do a nice rebuild on it. Br advised, this IS an addicting hobby !

Dirtracer115 wrote: So my question is what exactly is different on the 1100s versus the popular 1000s. I've done a good bit of research but info on the 1100s seem much more difficult to find than the 1000s. Like what is bigger on the 1100s the bore, stroke, or both? Are all other parts interchangeable? From what I've found it seems the cam grinds are different. Oddly partzilla.com has the same part numbers listed for cranks and pistons. And while we're at it are there any differences in the frames?

Try a google search on "kz1100 specs", the first hit is to a site with tons of specs on all kinds of different model bikes. You can compare the KZ1000 specs against the 1100 very easily.

Not sure why you are seeing the same part number for the pistons between the 1000 and 1100 since they are not the same parts. You might want to go back and look again.

Simple answer to your ?? is, yes most engine parts are the same between the GPZ1100 series and KZ1000J series. The cranks, heads, rods, camshafts, engine covers, cases ect will interchange. You can take the pistons and cylinders from a GPZ1100 / KZ1100 and swap them onto the KZ1000J block making it into an "1100". There is an exception to this, the 1983 and later GPZ1100 used the 18mm piston pins, your 81 uses the 17mm pin, Other than that pretty much everything will interchange. Also the KZ1000P engine is the same, that is the police bike
Here is some great info on the differences.
www.cavanaughracing.com/kzdata.html

Derp, looking up bore x stroke specs would prob have been much easier than cross referencing part numbers. It didn't even cross my mind lol

Exactly what I was looking for guys appreciate it. This bike already has an upgraded ignition system (haven't looked for the brand), kerker pipes, and when I rebuilt the carbs I went to pods and rejetted but once I get on the road I will tinker with the jetting and see if it could use a little richer jetting. I'm not sure If my speedo has been swapped or if it was a special option but my kz has 140 on the speedo. A couple odd ends like my new petcock that came in the mail today and she will be back on the road for the first time in several years

And this is my first street bike but not my first kaw. As a teen I beat the snot out of a kx125 for 7 years so I'm already a kaw fan

81 1100 vs 80 1000 only piston diameter is different.