TOPIC:

hello, I own a kz400 1977 but I'm having some issues with the carbs. I put pods on my carbs because my air filter was really dirty and took up a lot of space. I kept the stock exhaust and thought I might need to rejet my carbs but it didn't seem like I did. So I kept riding it then my bike started acting like it was running really rich so I leaned out the mixture. (This doesn't make sense to me because I thought with pods your carbs would need to get rejetted to run richer. ) But now my bike is bogging down and won't run unless I'm tweaking the throttle or have the choke on. I'm confused because my spark plugs are black like it's too rich.

Welcome, where is the quote from? Check your valve adjustments and ignition before going to the carbs.
Steve

Congratulations! By removing the airbox and installing pods on your bike's CV carbs you have won the opportunity to become a carb expert. I'm pretty sure if you spend enough money on jets, etc. and enough time you will be able to make the bike run ok. Not as well as with the airbox, but ok. Ed

That's okay one of the main reasons I got an oldie is the learning curve. Where is a reliable place to by carb kits?

jetsrus.com/

Pig wrote: . . . kz400 1977 . . . issues with the carbs. . . pods . . . bike is bogging down and won't run unless I'm tweaking the throttle or have the choke on. . . .

Pig wrote: . . . one of the main reasons I got an oldie is the learning curve. . . .

The learning curve has proven to be more of a learning cliff when dealing with KZ400 on pods, which will likely never perform at its best potential throughout all ranges of throttle as well as it does with the stock air-box configuration.

Click here > to begin your first homework assignment .

To locate topics here in KZrider on whatever subject, SEARCH is included in the menu under FORUM (in ribbon across top of screen).

Good Fortune!

Ifyou spend sone time reading the threads on this site regarding the KZ400/440 and pod filters, you will notice that most of them come to an abrupt end with no resolution. It seems that the carbs used on those models are especially sensitive to changes on the intake side. I found one exception, but the builder replaced the CV carbs with mechanical carbs, which are less sensitive.

www.kzrider.com/forum/11-projects/598595...400-d3-grimey#689125

Pig wrote: hello, I own a kz400 1977 but I'm having some issues with the carbs. I put pods on my carbs because my air filter was really dirty and took up a lot of space. I kept the stock exhaust and thought I might need to rejet my carbs but it didn't seem like I did. So I kept riding it then my bike started acting like it was running really rich so I leaned out the mixture. (This doesn't make sense to me because I thought with pods your carbs would need to get rejetted to run richer. ) But now my bike is bogging down and won't run unless I'm tweaking the throttle or have the choke on. I'm confused because my spark plugs are black like it's too rich.

First check your valve lash and ignition. Make sure it is set to factory specs.
If by leaning out the mixture you adjusted the idle mixture screws, set them back to
factory spec/best idle. That will eliminate the need to run with the choke on.
What filters are you using? The carbs do not like the air bleed hole on the inlet side
to be blocked like some filters do. You need filters like K&N or Uni that do not have
a step inside. Then we can work on tuning your carbs.


.
P.S. Also spray around your carb boots to see if they are leaking or not.
Do this with the engine running. You will notice a change in sound/rpm if
it has a leak. Carb or brake cleaner works best. Rpm will increase.
Be careful, do not spray around any ignition components.


.

.

I haven't done it on the diaphragm carbs, but rejetting the piston CV carbs on the early 400's was not very difficult, even without a wideband ... just seat of pants tuning. But if you've never jetted carbs before, you will have a lot of reading to do. And if you are working with the piston carbs, there are a lot of condition issues you need to address before you try jetting. You have to get very well acquainted with how to set the top covers so the slides move perfectly. You will also need to take a close look at the throttle shaft to make sure there is no air leaking through the bushings. That is on top of all of the basics... float level, needle valve condition etc. etc.

It is not a beginner's project for sure.

+1
Put the airbox back on,clean (or buy a new) filter,and ride your bike! In the meanwhile,research fuel/air mixture and its effects on engine performance.(theres a lot of stuff out there on the subject)
Im not a purist.Ive no problem with pods but it seems that its not just a bolt on deal. Theres a lot more to it.Im still learning.
Good luck.

I get putting pods on CV carbs to look cool
But here it is,when you open the throttle with the bike off
The slide does not move..the slide only moves when the correct amount of air passes through
The carbs uper intakes,hense the name constant VELOCITY,this is achieved by an air box,filter
And small cut away in the box ,the engineers at Kawasaki didn't use a dart board do come up with
The dimensions to make it all work , a lot of science here
Anyone who says they can set up CVs has no idea how good the stock set up WAS

richard wrote: Anyone who says they can set up CVs has no idea how good the stock set up WAS

Or maybe they spent enough time and effort to know how to do it.