78 kz 650 4 into 2 carb size

hello i have a 78 kz 650 that i have been running around for some time now, and i have been wanting to change things up a bit. i have a 1968 triumph 650 that i run with one 34 instead of 2 32's. and have been wanting to clean the look of my kz up, is there a formula for reducing the number of carbs to figure out what size i need or is it trial and error? or if anyone knows of a good setup that would be good. but i really want to understand the math behind it.

Won't work,2 carbs to 4 cylinders or 1 for all 4,look at your firing order.
If it does run it'll run like shit.

can you elaborate at all because im not sure i understand the fireing order all cars run off of one carb? just want to know the reason?

It's doable - the turbo 1000's used to run on a single carb. Not sure it's worth it, though. This has been discussed in the past, I believe.

1342
With 2 carbs you will have 2 pulses then nothing for 2 events.
With 1 Carb even fuel distribution will be a problem.

Nebr_Rex wrote: 1342
With 2 carbs you will have 2 pulses then nothing for 2 events.
With 1 Carb even fuel distribution will be a problem.

Agreed, but as I said, it's doable with one. And as I said, I don't think it's likely worth it.

running a single 42?? Kehin on my GL1200 I love the people who say you cant do that!
Good tourque smooth power.

Firing order doesn't matter gas is atomized into a vapor that fills the runners of the intake just my .02

I will dig some better pics up when I have time.





used a branch (harley fast guys)intake with PVC runners plumbed to factory intake done it in abour 2 hours.

Have 2 years maybe and 5000 miles without any serious problems (fuel pump went out experimented with corvette fuel pump with regulater settled on what I believe is a yamaha fuel pump free from the shop)

its just a matter of plumbing it,youre only feeding 2 cylinders at any one time anyway.

Nebr_Rex wrote: 1342
With 2 carbs you will have 2 pulses then nothing for 2 events.
With 1 Carb even fuel distribution will be a problem.

you can run a 2brrl or a 4brrl or 3 2s or 2 4s on a v8,why cant you run 1 carb on a 4cyl bike motor?
ive run many turbo charged bikes over the years with one big carb with no problem

a kz1300 runs 6 cyl off 3 carbs so why not ???

One of the members here put a single carb on a 650. It was several years ago. The carb was from automobile. Perhaps an SU carb ? Not sure. He made a manifold from inch and a half or two inch copper tubing. He did say it was relatively easy and not much tuning required. I'm thinking it may have been The Milkman or maybe Biquetoast and also that it was on the old site.

Here is the link for the milkmans thread,

kzrider.com/archive/viewthread.php?tid=23259&page=1