crank z900 and z1000

which of the two cranks/cases are best??



/Lars

If I was to build a 1000 engine.....I would want Mark II cases, trans and crank.

The Mark II cases are beefed up and stronger with additional supports and cooing fins.

The MKII crank is stronger and weighs more with a 16T tooth center gear.

MKII trans is stronger than others with approved 2nd gear.

but heard bearings and crank are stronger on the z900

Z900 crank is lighter but mk2 is stronger with larger crank pins.
All depends on what type of engine you want to build.
A big bore bruiser will want the MK2 crank but the lighter Z900 crank is more suited for a medium capacity café racer as it will spin up faster and rev out more.

The 900 cranks are lighter hence more hp with less weight. The 1980 MKII crank weighs about 5 lb more but has bigger pins that hold the crank together along with the bigger center pin. It depends what your doing with it. A crank used for drag racing takes way more abuse then a street driven crank. Your will never achieve the traction a drag bike has with a racing slick and prepped track which is where a lot of the stress comes from. If I were riding on the street a 900 crank would be good for any mods less then a turbo. The weight difference is noticeable, take a normal stock bike; a 900 crank will stall out easy if you start in 3rd gear. The 1000 crank walks right through it because it has more rotating mass.

also thought about the wight difference - just heard the z900 crank was the best!!

Gonna do a 1197cc with Mikuni WM33 and 38mm stainless header- havnt though about cam yet... wanna have a low/midrange torgue/power bike that is easy driven everyday...

Any suggestions or advice??

Think im gonna go with my z1000a and save the z900 for some other fun

I would go with any 1000 crank indexed and welded.
GPZ1100 unitrack cams are a good cheap upgrade if you can find some and fit some roller chain adaptor sprockets from APE but recommend shim under bucket valve adjustment.
Otherwise any fast road cam will work well with a head flow job to make the best of them,
Pitstop performance do their PSP cams (Andrews profiles) at a very reasonable price.

I would go with a 77 or 78 KZ 1000 15 tooth crank for your 1197.... most street bikes do not need a big pin MK II crank. unless you have a lot of H.P. , it's wasted money......it's hard to find a cheap MK II crank. If you do use a mk II crank you will also need the longer cam chain and 32 tooth cam sprockets....... Still ,I would have it indexed and welded at the very least.

im gonna go with the z1000a2 and then go for some torque.....

Im more into the looks when it comes to the bikes- but when its my own build i like to play a little with the performance
I have been working for a small custom garage here in copenhagen and usually the customers dont want to put money into the performance

I really like how you all are so much into all of this engine things - thanks

heres the donor...

lars,
do you work at wrenchmonkees?

leon

Yer you know them??

know em?
no.
just drooled over everything they build .

really cool to have a member of wrenchmonkees on our forum.

you guys do so much with kz's i am surprised it has taken this long for you guys to come around.

welcome.

you are in the right place for the legendary z/kz kawasaki model.

keep up the good work,show us all the pics you dare. :whistle: :lol:

leon