abused 1974 z1 900

I am trying to read a abused engines history can you help? The exhaust header was removed today and i found number two and four cylinder ports were washed clean, in the exhaust .Number 1 and 3 were full of carbon. This engine Used velocity stacks, that killed this engine on a dirt road. Check pictures please. What do you think about it? I will pull the head in about a month.

Will this bike run?

Not right now ,compression is shot, and there is 11 thousanths clearance on the two inner, intake valve shims.The head, cylinder,and motor was removed and worked not to many years ago. I bought it for less than 200 and the guy did not want to volunteer much history. He said it would do 140 mph!

I imagine removing the head and checking the tops of the pistons will tell the story. If you can get it near stock it is worth a lot of bucks.

You probably can find a set of pistons and the jug to match fairly cheap. Roy

I am getting indications to use a cheap 1000 j cylinder and pistons with the 900 original head. Supposedly I wont have to clearance anything like the block! Gaskets should work also for the J cylinder

I dont think you can run a 1000 j jug and pistons on kz bottom end without having machining done.

I think a few more changes also. The chain tower need to be changed I think.

It is a good mod and you probably will learn on here how to do it. Roy

Thanks people, I will hang around here for the great knowledage.

info from ape:
KAWASAKI KZ1000 ENGINES

There are two different KZ1000 engines. The first is the Z1 type which was built between 1976 and 1980. The second is the 1000J, or "J model" as it is called, and was built from 1981 until present ( currently only available in police motorcycles). These engines are different, but some of the parts can be interchanged, and this has caused much confusion. We hope this makes everything clearer.

The first example is simply a big bore Z1 900. This engine came with a kick starter and electric starter. The cam chain tensioner hole in the cylinder block is a rectangle. The ccs cast on the cylinder is 1015. The later "J model" has no kick starter, and the cam chain tensioner hole in the cylinder block is round. The cc's cast on the cylinder is 998. This engine also became the GPZ1100 in 1981 and '82, and virtually everything between them is the same. (The '83-'84 GPZ1100 was changed). Cylinder blocks and lower engine cases are NOT interchangeable. You can not put a J model cylinder on an older style lower end, and vise versa.

Cylinder blocks.. Not interchangeable. If you have a J model block/GPZ1100 block you must use a J model or GPZ1100 cases.

Crankshafts... Early KZ1000 used a roller type cam chain and the crank has that style center sprocket. J model used Hy-vo style chain. J model cranks can be used in early lower end if the center crank pin is changed to one with a roller chain sprocket. The J model connecting rods are approx 1.2 mm shorter than early style rods.

Cylinder head.. J model head has larger valves and ports. This head can be used on earlier style cylinder and lower end by installing APE #CCIA cam chain sprocket adapter in head . How to tell which head you have.. Early style heads have four factory drilled and tapped 6mm holes in the center to bolt in cam chain idler gear. Z1 900 heads have 6 mm exhaust studs, KZ1000 8 mm. On the J model head, the four cam plugs at the ends of the camshaft areas are bolted in, on the early style head, they just push in and the valve cover holds them in. The J model / '81-'82 GPZ1100 cylinder head has a larger combustion chamber than the early style head. When these heads are used on the early style motor, a compression ratio drop of about 2 full points can be expected.

Pistons... All pistons have 17 mm pin holes, but the J model/ '81-'82 GPZ1100 pistons have the pin hole lower in the piston to make up for the short connecting rod. All J model and early '81-'82 GPZ1100 pistons are the same ( '83-'84 GPZ has 18 mm pins ) Therefore any '81-'82 GPZ piston can be fitted to a J model engine to make a big bore engine. Pistons for the J model / '81-'82 GPZ1100 can not be used in a motor that has an early style long connecting rods unless a spacer plate is used under the cylinder block to compensate. If early style KZ pistons are used in an engine that has the short J model / '81-'82 GPZ1100 connecting rods, a special short cylinder block has to be used.

We have tried to make this as clear as possible. When ordering your parts from APE, let us know which engine you have, or if you are mixing early style and late style parts, let our tech/order department know and we will see to it that you get the correct parts combination.

hth,

leon

Charles Nix wrote: I am getting indications to use a cheap 1000 j cylinder and pistons with the 900 original head. Supposedly I wont have to clearance anything like the block! Gaskets should work also for the J cylinder

If you truly have a 1974 Z1 there -- using anything newer than at MOST the 1976 kz900 motor, the last year of the 903cc cylinder.....


....it would be like finally getting a date to the Prom with a really hot gal, and bragging about it to your Mom, then your Mom shows up with the family with cameras and you show up with the hot girl's cousin who is a fat, chatty zithead.

Mein gott you have a diamond in the rough, some of us DREAM of paying $200 for a 1974 Z1
mein gott.


When Dad finds out you embarrassed the family, you're putting yourself through college.


The Z1 motor had a HUGE production run. Go to ebay, search on "Zedder" and "Kawasaki cross reference" and spend the $20 to get his parts cross reference, then you'll know EXACTLY what other Kaw models you can source parts from on ebay for your mighty Z1.


It would be like putting an old Gremlin motor in a new Lamborghini.

It would be like getting accepted to Harvard then going to University of Phoenix instead.

It would be like walking up to a banquet table when you're very hungry, there's turkey, there's prime rib, there's a McDonalds cheeseburger, there you go grabbing the burger.