CR125 single carb on a KZ400?

I bought a second 1976 KZ400 for the engine and wiring for my new gokart project. As soon as i got it home, i removed the carburetors to do a cleaning. I was very disturbed to find that most of the clips that held the carbs in were loose and it looked like somebody tried working on them in the past. The choke plunger was missing out of one carb and it was just an open hole. Also, the choke arm was very loose and the plunger on the other carb was stuck. I removed the top caps and found that the constant velocity pistons were seized up and they were missing the springs. I removed the float bowls and found them full of white powdery stuff like oxidization but like really bad. The pillars on the carb bodies that the pin slides through to hold the floats in place were broke off. So, i disassembled the carbs completely, split them up, and decided to maybe put them on ebay for parts. Since i cant use those carbs, i have been looking for another set. All of the sets i found so far are either expensive or the wrong ones. I then found a video on youtube of a 1976 KZ400 Cafe that had a single carb on it with copper plumbing brazed together as the manifold for the carbs to fit into. Heres the video



I was thinking of doing the same thing with mine. Do you guys think there are any down sides to this? The only thing im afraid of is that one cylinder will run lean or something and ill burn the valves out of it. The carb is off of a CR125. Its a 33mm keihin. i was thinking of doing a single one or, getting two and doing 1 individual carb on each cylinder.

well if you can run a turbo bike off a 38-42 flatslide i dont see why it wouldnt work.

so its a yes then? i cant tell if thats a funny way of saying no:D

I don't like to diss anyone's work, in fact I love what they're attempting to do, but it did have a horrid flat spot in the video. I hope they have success, it'll be awesome.

It'd probably be better if they reworked their copper fabing a bit, and got it set up more like the intake on an old Triumph 500 Tiger. It would feed the cylinders more evenly.

yea, see im worried that when i do this, cylinder 2 will get first dibs on gas and cylinder 1 sill run lean and ill burn the valves up...

so what if i set it up with one individual CR125 carb for each cylinder? i would have to set up the throttle kinda funky but do you guys think it'll work?

as long as carb is centered between 2 cylinders you should be fine,kind of a homemade tunnel ram! :laugh:
hell harley twins run one carb

About 23 seconds into the video you can see how they have the 2 cylinders coming together to a T on the copper intake, and then they have an elbow on it so they could miss the center down tube of the motorcycle frame.

You said you're going to be putting it on a go kart, so you could eliminate the problematic elbow, and just have the carb straight off of the T (centered like Plummen said). That would probably work fine. I doubt that a carb off a 125cc is going to produce anywhere near the CFM provided by the original 2 carbs, but surely enough for a go kart application.

SWEET. Ill go get some copper plumbing tomorrow:D Im going to take pictures of the bike tomorrow so you guys can see it. Thanks for all the replys, im not done with this thread yet though.

Capt America wrote:

About 23 seconds into the video you can see how they have the 2 cylinders coming together to a T on the copper intake, and then they have an elbow on it so they could miss the center down tube of the motorcycle frame.

You said you're going to be putting it on a go kart, so you could eliminate the problematic elbow, and just have the carb straight off of the T (centered like Plummen said). That would probably work fine. I doubt that a carb off a 125cc is going to produce anywhere near the CFM provided by the original 2 carbs, but surely enough for a go kart application.

well if you can feed an 1197 turbo with one 38-42 flatside 2 cylinders at a time that little motor shouldnt be a problem

My god, what is that beast? thats magnificent.. lol

thank racer54 for that version of my same project,mines on the back burner still! :laugh: