How many r's can a kz 1000 buzz before damage

Yeah at high speeds a plain bearing crank is best. When you have full hydrodynamic lubrication you're getting little to no wear.

Is valve area the primary difference in feeding a bike at 8,000rpm's and 16,000rpm's?

I am working with 650 numbers but a 33mm valve has an area of 855mm's squared.

An R6 has 2 27mm intake valves so that is a total area of 1146mm's squared

If a ks650 were to be fitted with 38mm valve (having an area of 1134mm's squared) would that give it the ability to make power in higher rpm's?

I know the general belief is why try to do that to a 650, and I am not even sure a 5mm larger valve would even fit in the head I also know that the larger, much heavier valve would float at a lower rpm (without wicked heavy springs or lightweight materials).

But what I am asking about here is the theory. Which could be applied any ones questions about rpm's and these 2 valve motors.

A lot of the new 450 ATV motors that have lots of valve area and get spun up good are breaking con rods. And it's not juse one brand either....

Once it was popular at some biker events to drain the oil out of a jap bike, lock the throttle and let it rip 'till it blew up.

You'd be quite surprised at how long a KZ900 will run WFO with no oil before it lets go.

The likelihood of missing a shift and over revving a stock cammed KZ1000 to the point where you hurt it is very unlikely...

when I had my Kz on a dyno a couple of months ago,it was still making power until the rev limiter shut it off at 9500 rpm.that would have equated to 125 mph in 5th gear on the street.The bike will never see 9000 rpm again,but Im glad to know that if it does it isnt going to grenade.These old bikes are awfully well put together.Mama Kaw should be proud.bj

might i suggest building it in a suitable fasion based on the way it will be ridden? a motor thats making power at 9500 is wasted in a bike that spends most of its life at 5000-7000 rpms in my opinion anyway

Not sure how to respond.Other than V and H pipe,jetting to match the pipe and a Dyna S ignition and coils,plus a Satrab oil cooler,bike is pretty much stock ("J" cams installed this weekend)..Unless the PO did something to it before he stored it in pieces 20 years ago,it just happens to be a very good running old bike (after 2 years of putting it back together)..So,I didnt "build" it to make power at 9500 rpm - it just does (plus I am no engine builder)..If I ever have to tear it down and redo it,I will certainly heed ur advice.However,the way the bike runs now,it will probably outlive me in its current state.

Way back I had a riding buddy that was also a drunk :laugh: Every now and then he'd get an alcohol induced case of foolishnes going and rev his stock LTD until it broke up.

There was no rev limiter on the bike :woohoo:

Never dropped a valve, never tagged and exhaust valve...nothing broke. The bike just took it like a champ and kept on running.

It's nearly 30 years later. He quit drinking but still smokes pot constantly. He's not a whole lot smarter and his 1980 LTD is still being punished. He's in Florida now and his big kick is trying to run with the kids on Busa's across those long bridges they have down there.

Motor is nothing special, just a 1075 with 2x cams, 29 smoothbores and a 900 crank. It's top end has been rebuilt several times over the years but has never blown up under his abuse...

This guy could break a cannon ball in a sand box with his bear hands...but he can't seem to over abuse a KZ motor :woohoo:

Why is that?

Because it's a mild build on the motor. No big valves, no big cams, nothing to really push the mechanical limits and clearances when the motor is revved to the bottom of the tach.

Everyone has seen the Mad Max movie. 30 years ago, that was us guys being out of control and over the top. These KZ's don't need to be tricked to the max to do big smokey burn outs, dougnuts, wheelies.....Just crank that bitch up and let 'er rip.

hocbj23 wrote:

Not sure how to respond.Other than V and H pipe,jetting to match the pipe and a Dyna S ignition and coils,plus a Satrab oil cooler,bike is pretty much stock ("J" cams installed this weekend)..Unless the PO did something to it before he stored it in pieces 20 years ago,it just happens to be a very good running old bike (after 2 years of putting it back together)..So,I didnt "build" it to make power at 9500 rpm - it just does (plus I am no engine builder)..If I ever have to tear it down and redo it,I will certainly heed ur advice.However,the way the bike runs now,it will probably outlive me in its current state.

i didnt mean anything personal,its just everybody seems to get hooked like a big fish at some point and try and build a motor that would be right at home in a 400lb bike built for the track and wonder why its so tempermental on the street.been there and done that myself :laugh:

larrycavan wrote:

Everyone has seen the Mad Max movie. 30 years ago, that was us guys being out of control and over the top. These KZ's don't need to be tricked to the max to do big smokey burn outs, dougnuts, wheelies.....Just crank that bitch up and let 'er rip.

Well said.

i've missed a lot of shifts from second to third ect.....and watched the needles go away fast many times...seems to not affect the bikes much...i'm sure it don't help em either...but missed shifts...especialy with rear set linkage or a passengers wheight changing your normal toe touch.....are not gonna eat a normal motor...imo


these motors used to be bullet prooof in my mind before i found kzr and all the "builds" with issues....i've seen some pretty sorry kz's that keep on rrunning...tons of em.....

trianglelaguna wrote:

i've missed a lot of shifts from second to third ect.....and watched the needles go away fast many times...seems to not affect the bikes much...i'm sure it don't help em either...but missed shifts...especialy with rear set linkage or a passengers wheight changing your normal toe touch.....are not gonna eat a normal motor...imo


these motors used to be bullet prooof in my mind before i found kzr and all the "builds" with issues....i've seen some pretty sorry kz's that keep on rrunning...tons of em.....

quit using the clutch when ya shift with those size 18 feet of yours! :laugh:

like this???


(youtube)

testarossa wrote:

larrycavan wrote:

Everyone has seen the Mad Max movie. 30 years ago, that was us guys being out of control and over the top. These KZ's don't need to be tricked to the max to do big smokey burn outs, dougnuts, wheelies.....Just crank that bitch up and let 'er rip.

Well said.