900 crank in a 1000??

So a guy mentioned to me that a relatively inexpensive way to give my KZ1000 a little pick up was to swap out my stock crank with a stock 900 crank from a 70's KZ900. Anyone heard of this? Anyone have any opinions and/or proof to back this up?

it will definately let it rev quickerbut will also vibrate/buzz a little more.i might suggest a little longer swingarm because your bike will tend to aim for the stars after this mod when you lay into it hard !:laugh:

a worthwhile addition or no?

yess!! also to cut down costs

it depends on what you want to do with it,if its a daily driver i wouldnt go to all the trouble involved unless i was tearing motor down for a rebuild.you could do some headwork and maybe a small set of cams a lot cheaper and easier.biggest advantage of the 900 crank is its lighter and lets motor rev easier,but if the motor is choked down upstairs it will just run out of breathe a little quicker

Might be worthwhile in a race motor, wont do squat on a stocker in mho

I have to agree with Plummen and others...

Unless you're trying to shave weight for serious racing what will it gain you. I mean, for what, 5 to 10 pounds if that, ain't going to do a damn thing that would be seriously noticeable.

Hell, save yourself the head ache for by changing your cam, carb's and exhaust/baffle will buy you way more power than required for daily riding than messing around with your crank.

Then again, WTF do I know, please dis-regard if I'm talking out my ass....

OMR

it is not inexpensive but HELL YEAH!!! this is a performance enhancement!!!

less rotating mass(6lbs approx.)will let the bike rev much quicker even with stock compression and stock valve sizes.
get it matched with a good gear on the final drive and you'll be hovering the front wheel on serious acceleration.

z-1 is 37 lbs and the other kz 1000 are 43 approx

good start on the basics of a fast engine. welded crank and back cut 2 and 3 gear in the trans.

Maybe I read it wrong but it doesnt sound like a race motor to me, hes asking for a little more power in a stocker. There are lots better ways to do that then changing cranks. I doubt you could tell the difference in a stocker. Thats my opinion anyway. I have a stock Z1 and one powered by a 77 1000. There is no difference in power I can feel and I have 28mm carbs on the 1000 motor. Your bike & money, have at it

I was just asking what people thought. It isn't something I'm seriously considering, but I was just curious what people thought.
I am keeping this motor pretty much stock. Hell, at this point if the bike ever starts again I'll be pretty damned surprised.

Bicycle Lee wrote:

I was just asking what people thought. It isn't something I'm seriously considering, but I was just curious what people thought.
I am keeping this motor pretty much stock. Hell, at this point if the bike ever starts again I'll be pretty damned surprised.

C'mon now....don't write yourself because of a couple setbacks. You're not the first and won't be the last to have things go wrong. Learn from the mistake and move forward with knowledge. That's how all the pros do it..belive me, they break shit all the time to get ahead!


PS - It will rev quicker with a 900 crank and as a result, more RPM sooner, will accelerate a little better. Certainly not the most prudent route to stronger acceleration though. Power though, comes from the top end mods. Even drop in cams will give you a nice boost.

You can take these motors from mild to totally absurd and anything in between:)