Newly rebuilt KZ1000P engine will not rev...

Hard to tell because of the video quality but it looks like maybe you didn't install the needle jets in the carbs




Have you run it with the exhaust system, at least the header, bolted on?

The pictures show no airbox attached to the carbs. Without that it will run like crap - period. Hook up the airbox and give it a try; you may be pleasantly surprised at the improvement. Ed

The last time my carbs were synchronized, I found that it doesn't take much mis-adjustment to throw the idle out of whack to where it runs like crap.
Get that on the money, and Wow!

650ed wrote: The pictures show no airbox attached to the carbs. Without that it will run like crap - period. Hook up the airbox and give it a try; you may be pleasantly surprised at the improvement. Ed

x2 .....thought it was supposed to be jetted already...my bad

Well guys, all of the above I've done, checked, and double checked. This is why I'm so stumped by this. I did put the stock airbox and filter on after those videos were taken, it sounds exactly the same. Fuel levels are all proper, needle jets are in fact installed,and spraying carb cleaner into the carbs while its running, does get a small rise out of it, but it still sounds blubbery.

All that popping at low RPM sounds like a vacuum leak/ lean. Or the carbs out of mechanical sync.
Watching the slides try to lift in your video, are the slides Indexed correctly? That's where the hole in the bottom of the slide is facing the engine/ vacuum side. There is a notch at the diaphragm to be set in place, and then the slide should be indexed.
What about the diaphragms themselves, is there a leak here, or at the lids?
Slides assembled correctly, needle with clip in first then plastic retainer, then spring, spring centered in cap, diaphragm fitted correctly. Correct needles? You can check the # at Kawasaki.com parts fiche for your model.

Put your location in your user profile, so everyone can see where you are.

Motor head - So I've checked all the vacuum and just for good measure replaced all the lines. They were 22 years old anyway, why not. Also replaces the carb boots and sealed them to the head. Checked everything and haven't been able to find any leaks. I did index the slide diaphragms, though I never checked where the hole was oriented. I imagine that if the diaphragm is indexed then those should be too, but I'll check anyway just to be sure. No rips or holes in the diaphragm itself, could there still be a leak out of the lid?As for the needles, these are the ones I pulled out of it, and it ran then... Thanks!

You have done a Leak Down Test, which you said all seals are fine. What about Compression? have you checked compression? I know you say you have rechecked the camshaft timing several times. But did you remove the gears from the cams? IN and EX for sure installed correctly? There is a pdf version of the service manual in my signature which will cover your engine.
With the 1-4 T mark lined up, with the valve cover off, post a picture of the cam gears where they line up to the head. Also the Right End side view of the motor, showing the cam lobe relation to the valve cover surface.
Look here for a picture of how the cam lobes should look if correct. Older KZ motor but cam lobes are still set up the same, although gears and marks are different. www.kzrider.com/media/kunena/attachments...LobeOrientations.JPG

Daveo - Synching the carbs is the one thing I haven't done yet, as I was waiting till last for that. I have not adjusted any of the mechanical linkages, and they ran pretty good before, so do you think this could cause the motor to run so poorly?

Motor Head - I'll take some pictures of the cam position tomorrow. Leak down test was flawless on all cylinders. Compression was questionable; here are the numbers:

1 2 3 4
dry 125 120 105 125
wet 135 145 110 145

My service manual lists 120 psi as minimum and 160-190 psi recommended. I'm not sure what is up with cylinder 3, but my compression gauge is quite old. Maybe I should recheck them all...

can you borrow a set of carbs to try?

:whistle:

Those compression #'s should be higher of course.
Can you tell everyone what was done for the rebuild? Was it just rings and a valve lap in, or was it more thorough?
When you did the Leak Down Test, was this with a Tool with gauges? Leakage low % like <10% on all?
The low compression could be do to late IN cam timing, which would lower the signal through the carbs, making it difficult to get the CV slide to operate. Is your upper cam chain slider/ guide in the valve cover? his applies pressure to the cam chain between the sprockets, if missing can cause issues. I bought mine with it missing and 3 cylinders had bent valves after it skipped time.