KZ400 Carbs

So I started overhauling the carbs on my 1974 KZ400 and the bank with the choke is all messed up. The float pins, choke mechanism and vacuum slide are all frozen from varnish. I found a replacement carb bank and was wondering a few things. First, I want to run pods and understand that jetting might have to be done. Are the original carbs worthy candidates for pods and jets? Has anyone ever tried a set of those Chinese carbs? They are so cheap on ebay. Do they accept the pods and jetting better?
Basically just want to get this bike going and keep the low budget theme going. This kz will have nobbies setup as a scrambler. I want mostly torque. I also plan to build a scrambler exhaust, 2 into 1. This will be a trail, wheelie, stunt scrambler. Not much highway use. No emissions here in CT neither

If the problem is varnish, it can be removed with a good carburetor cleaner. You will need to completely disassemble both carburetors. The metal parts will need to soak in the cleaner. How long that takes depends on the cleaner and how bad the parts are. You will need an old steel e string from a guitar to insure that all the tiny passageways are clean. All of the gaskets and seals should be replaced with new ones.
If you decide to use the replacement carbs, you should still do this, since you have no idea if they have ever been cleaned.
I know of only one guy who has tried a Chinese carburetor, and it required quite a bit of work to make it sort of functional.
Pod filters and an aftermarket exhaust will require rejetting the carbs.

Thanks for the reply. I'll be honest. I broke the slide and the mounts for the float. Thought the pin slid out of like on other carbs. The top of the slide broke off when I pried on the slides. Ill work them from under next time.. My mistake. So it sounds like I need a new set of carbs. I do plan to give whatever set of carbs the works. I have a gallon of the solution. It loosened most of the varnish down, but now I need parts.

Heat breaks down the varnish easily. Use a heat gun on the carb body and the slide will fall out under it's own weight. Too late now though...

That's good information. I should have known that by now. Also, the choke is still stuck, so Ill get that heated and removed.

Nessism wrote: Heat breaks down the varnish easily. Use a heat gun on the carb body and the slide will fall out under it's own weight. Too late now though...

It was the throttle shaft that controls the butterfly piece that was stuck. Put the heat gun to it and she gave up. Thanks so much. I plan on rebuilding a a few more carbs. Absolutely enjoy this so fn much. The carbs looked so pathetic before I dunked them. Between the gallon of solution and my baking soda blaster, these things shine up nicely. Also, yes, you are absolutely correct about those small locations with the string. I have some antenna wire from work that I used on my 82 cb750SC carbs. There was a 40 page pdf write up that I was able to follow, it was incredible, after a few months of headache, that bike is an animal. My goal is the same. Stock rebuild, no leaks.

Wish I knew the trick with the heat gun back when I restored it. I had a clogged accelerator pump nozzle that was pointing inside the carb. Like a tiny 2 mm squirting nipple to clean out. It sits in the middle of the carb and faces inward so you have to make "hooks" to clean it...omfg.....It was packed in there and down into a rail. Wouldn't clean out for the life of me. Ended up eating away at it with CLR. But now I can add heat to my bag of tricks. Thanks bro!

If you are going to put pods on the Kz400 you will have a lot of jetting to do regardless of which carbs you get.

The piston-slide Keihin can work fine with pods but they are super-complicated with the various multiple stacked fuel jets, and air jets but it can be done. The real problem is that most of those carbs are pretty worn out by now. By this I mean the slides have rubbed off the coatings inside the carb body and slide covers and the throttle shaft bearings are worn so the shaft moves around and causes little vacuum leaks at the ends.

If you can get an old set that hasn't seen a lot of miles, then it should be fine.

The Chinese replica VM30 carbs are much simpler, but everyone says to not use them and that they are junk. The ones we bought seemed quite nicely made and worked out of the box. I'm not sure what all the complaints were for specifically. There are some issues to be aware of and you will have to do some adapting to get them to work.

Obviously a split throttle cable will be the main issue. We ended up modifying a Honda CB200 throttle cable. They are available on ebay cheap. Having two choke levers to juggle is not too bad once the jetting gets more dialed in. You can usually get it to start just using one choke. We just jammed them into the stock Kz400 carb holders, but you will probably want to get aftermarket holders to fit better.

The biggest thing to realize is that the main jet on the replica VM30 cannot use Mikuni VM30 main jets. The threads are different. This actually ends up beneficial since the real VM30 jet threads are not common threads. You can use main jets from a different carb. I used mains from a Teikei TK22 cabrs since I have a bunch of them around.

Somewhere I have a Kzrider thread with the jetting details for the Keihin piston-slide carbs on a Kz400.

Here's the build thread including the Chinese carb info. It's a long read.
www.kzrider.com/forum/11-projects/611489-dueling-kz400-s