KZ400 2-1 Intake

madmatt1

Been Around the Block
I've been kicking around the idea of making one of these for my 1975 KZ400. Anybody here have any success
stories? I'd kinda like to make one out of copper... Is it possible to braze copper to metal? The idea would be to burn the rubber off of the stock carb holders and use them as "flanges" for the 2-1 intake. Just an idea..
 
There is a guy that makes copper 2-1 intakes specifically for the kz400...can't remember the website, but I think they were around 80.
 
When you say braze copper to metal, I assume you mean steel or aluminum (copper is, of course, a metal)? In both cases it's possible, though its much each to solder with copper and aluminum can be tricky.

Also, you probably won't be able to reuse the metallic parts of the stock manifolds. The metal actually isn't very thick and there isn't enough of a sealing surface unless you make some pretty drastic changes. And then you're probably better off just milling some new ones...

Finally, you should be aware that what you're doing is likely to be a performance downgrade.
 
Thanks for the answers guys- great info.

Bobbed_out- Thanks for the link, I have actually come across those in my searches.
The thing that doesn't do it for me is that you have to reuse your carb holders. These are basically
unobtainable for my bike (1975) so it wouldn't do me any good :(

Sonreir- yes, I meant braze it to steel. (It's been a long day ::) ) I just like the idea
of doing this because that way I could use what I already have. I have 0 skills when it comes to machining- wouldn't even know
where to start. I am sick of spending time and money on this bike. I don't have the stock airbox and exhaust to use, so this seems
to be the cheapest and easiest way to be able to actually dial it it. I have tried but can't seem to achieve this with my stock CV's.
This bike is slow no matter how you slice it, so I'm not worried about the performance. Running well with a lower overall potential
would be better than not running.
 
The stock carb holders are unavailable but there are alternatives. Take a look at this thread on the KZ400 forums site where a couple different options are shown to work:
http://www.armbell.com/forum/viewtopic.php?t=6202&highlight=mikuni+boot&mforum=kz400

1. The carb holders from some KZ1000s will work if you use a rat tail file to open up the mounting holes just a hair.
2. There is a Mikuni set of holders that matches up perfectly and is easily available anywhere including Amazon.

The drawback to both of those holders are that they are about 1/2" - 3/4" shorter than the stock holders so there may be some fitment issue if you are using the stock carb boots and air box. But since you are using pods then you should be in good shape.

Sorry I don't mean to sidetrack this thread, but I don't see the big attraction of going to a 2 to 1 on the KZ400s, though I know several folks have done it. I guess I understand the simplification of 1 carb instead of 2, and parts are not available for the stock carbs, and the stock CV carbs suck and don't run well in anything but the stock airbox. But why not just switch to a pair of Mikuni VM30s instead? Then you can run pods and tune for it easily. That seems like much better option to me and that is what I'm planning on doing eventually.
 
No man, that's fine! Like I said, just a thought- I appreciate any opinions / info I can get on the matter.
I've thought about going with some VM30's, but haven't really wanted to put that kind of money into the bike.
I'm sort of leaning towards getting the bike functioning well enough to sell it, and move on to other projects that
I'm more interested in. I'm sick of this bike, to be honest. But maybe I can score a deal on some VM's and get it done that way. Thanks
again for all the info-
 
Sonreir does group buys I'm the Vm's...I got a set for my kz400 from him and he just started another group buy thread in the selling section.
 
$15 airbox over at the kawasaki twins forum http://www.armbell.com/kz400/viewtopic.php?t=18253&mforum=kz400
 
Bobbed_out, have you got those VMs setup on your KZ400 yet? If so, I'd love to see some pics and hear details. Did you go with Vm30s? Like I said, I'm very close to doing the same thing myself. My bike is running well with the stock carbs with the stock intake. But I eventually want to "clear the triangle" and go with pod filters. I figure I could save myself a lot of heartache by getting the VMs. Do you have a build thread for your KZ400? [Sorry for the off-topic, gents - as you were!]
 
I haven't started on the kz yet. I have just been collecting parts, plan on starting it this winter, sorry. I got the 30's...I'm sure someone else here has successfully put them on there kz though.
 
$15 airbox over at the kawasaki twins forum http://www.armbell.com/kz400/viewtopic.php?t=18253&mforum=kz400

I actually found an air box- it's different than that one though- it's steel. The boots were gone so I've made up some
new ones out of rack & pinion boots. I'm guessing it should work fine, but probably won't look all that great considering there are no side covers on the bike. I don't really care though- just want to get it running well enough to sell it at this point
 
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