KZ 1000 Air intake

Untitled by Joe Herriges , on Flickr

I picked up this just to have it in case I ever go back to completely original . I found it interesting how the Kawi engineers made this with the 2 air intake runners almost to the bottom of the housing, running past the larger intake port, and the inside of the larger intake that attaches to the air box with a wavy interior. I guess there were good reasons for the way it was done .
Just had to comment because I assumed it was going to be just two holes in the top, and the interior of the main passage would be smooth, I found it interesting that they designed them like this.

I agree, there must have been good reasons. Here's an article quoting a Mikuni engineer that I found interesting. Ed

I've told this story before but when back in school I had an XS400 Yamaha and no money for OEM air filters. Bought some cheap Uni pods but couldn't get the bike to run right. The XS400 used long intake runners with the air filters (2 of them) hidden behind the side covers. Wound up reinstalled the runners and clamping the pods onto the ends and then the bike ran great.

I had an xs400 too …same thing I put pods on it ran like crap. played with shiimming the needle and the pilot still nothing ,then put the pods on as you did with a piece of pvc, and it ran good. I think getting them in still air was as much help as the tube Although I think the oem may have been better. I had got it for my wife but she never really liked riding. That was a fun little bike I road the heck out of it.

Right now on the KZ I am running the air box with a K&N in place of the stock filter, the jets,, I am assuming, are a dyno jet kit from about 1985 but I cannot confirm that, and its good everywhere but full throttle, it breaks up at full throttle, If I remove the air cleaner it gets better so I am assuming rich on the main, the mains are not labeled and I looked very closely at them,

My plan is to replace all the rubber pieces intake manifolds and the air box boots, then go to 107.5 mains which I think were the stock main jets, They were in the same box as the stock needles so again I am assuming, I plan on running the needles.
The info I find on the 28mm pumper carbs which is what it has (1980 kz1000) is they ranged from 100 to 107.5 that is from looking on partzilla and such at OEM parts.

It will be interesting to put that piece on and see if it runs better worse or the same!

I have also read here that removing the screens in the main air box and attaching a K&N under the seat to the air box and removing the filter from the stock location works well.
Im not looking for power Im looking for a great running bike, So my inclination is to go back to stock first.

I've read a fair number of oil analysis reports on Bob Is The Oil Guy and Blackstone and K&N's often lead to high silicon (dirt) levels in the oil. I used to run them before reading about this but not any more.

I have heard that also , I have also heard that K&N pods are a leading cause of carb slide wear mainly on the CV flat slides like on the GSXRs and such, The fine grit wears the the plastic inserts the slides ride in. I have seen this myself but I never thought about the filtration until I was told that, it made sense to me.
Im not sure I put enough miles on to matter much. I might get 1500 mile a year on the any one bike but not much more, but if I was doing high milage I think I wold do as you did and switch back to stock,
I have also been told that the UNI type foam oiled filters when cleaned and oiled regularly work well and I also know that some use a thin oiled foam pre filter over the K&Ns when off road riding,
I have never seen or read actual testing though.

Your bike will run better with the end section back on, i know this from experience, my existing thou was set up for performance and there was low end poor running, so i put back to stock aside from an aftermarket exhaust, and rejetted from that point, i now have a bike that runs clean my and smoothly right through the rev range.