TOPIC:

I'm sorry if I am beginning a thread that has already been answered, however I have scoured the site and haven't found what I'm looking for.
My carbs were rebuilt using the recommended kit from Keihin including new diaphragms. Here is my problem: It starts beautifully, idles at about 1000 just fine. However, I am unable to take the choke off more than 1/2 way and if I give it throttle it dies. I have tried adjusting the pilot screws to the "factory" specs according to the service manual (all the way in lightly, then backed off 2 1/4 to 2 1/2 turns. I have also tried going less and more. Both carbs are running (?) the same way. Any help I can get would be greatly appreciated.

Thank you,
Kate

Have you tried adjusting the idle screw ? After the engine has warmed up?
See kz400.com/TechnicaltipsFrameset.html and scroll way down for Adjusting Carbs 1977 model

If that doesnt work then possibly dirty pilot jets.

I'm not familiar with kz400 carbs and they may vary from model to model. It would help if you put the year and model if availabe in your signature.

Thank you. I haven't tried that. I don't know if my dad did. I downloaded the technical tips. Will be reading that tonight.
I didn't know about the "signature"...wasn't sure what that field was for. I did however put the year & model in the subject line...

What are you running for an air filter and exhaust?


.

Pods with extensions & straight pipes. Those have worked perfectly for a number of years. (Yes I did replace the filters so I know they are not dirty). I haven't put the filters on to adjust. Is that one of my big mistakes?

The filters should be on the bike.
There is some useful info on rejetting the cv carbs on a 440 in the kink below.

www.dotheton.com/forum/index.php?topic=39120.165

UPDATE!
Well, I don't know why this didn't enter the noggin....When the pipes were cut by P.O., there was no baffling. The carbs were not rejetted, therefore, no back pressure. I put (don't laugh...ok go ahead), a Brillo pad in the pipes -only thing I could find at the moment-and secured it with a piece of screen and clamp. Fired it up. Ran pretty darn smooth. Seated the screws, backed off about 2 1/4 turns and was able to take the choke off almost all the way. Well now, don't I feel foolish? FYI burning brillo pads, the ones with soap really stink.

Check out the mini pipe baffles / drag pipe baffles, you can pick up a pair cheap off of amazon or ebay. It will quiet down the pipes but provide the backpressure you need. I put 4" long ones in my 1.5" diameter pipes I ran back from the headers, bike runs great. Just be sure to weld or bolt them in so you don't shoot one out the back

UPDATE:
Fitted the pipes with baffles/extensions similar to 77Davo. Was running great-ok, greater. New problem. NOW, it is cutting out when it warms up. Once it cools, it fires right back up and runs until it gets warm (2-3 minutes) Here is what has been done:
COMPLETE clean & rebuild of carburetor. (All jets cleared, needles replaced, seats cleaned or replaced if removable; floats adjusted, fuel level minor adjustment, ) New plugs, just because. No, the old ones were not fouled at all. I have a hose on the breather-no filter yet. No fuel overflow, no smoking, etc. Thoughts, suggestions PLEASE!!!

Coils or valve adjustment.
Steve

You can test to see if the coil is failing after warming up this way -

With the engine cold use a hair dryer to heat the coil up, then see if the bike starts and runs normally. If the bike runs poorly, as it currently does when the engine is warmed up, there's a fair chance that the coil is failing when it gets warm. Ed

I will try that this afternoon!