cv carb advice plz/ kz400

Happy memorial day!.... It's raining here in Seattle so I think I'm going to take the time to clean my CV carbs yet again. The main reason for doing this is that I have a really hard time keeping my kz400 idling when it's cold. It'll start right up with the choke on and stay idling for about enough time for me to put on my helmet and gear but then the RPMs drop and if I don't blip the throttle, it'll stall out. If I take the choke off at this point the same thing happens... I have to stay on the throttle consistantly to keep the bike from stalling out. After I ride for about 5 mins, while throttling at any stops I make to keep the bike running, the bike will start to run normally and no problems Idling. Basically, it just seems to take a little too long to warm up.
Also, I'm getting a little sputtering at higher RPMS in 2nd and 3rd. Yes I do have pods, but I have had the bike running with out these problems. So I'm going double check my work, clean the slow jet, pilot jet and needle jet. all jets again and see if that helps.

any suggestions on the idling issue when cold? Or is this just par for the course with these older bikes...but again, for a brief period when I first put it back together (a couple of months ago) I don't think I had these idling issues even when the bike was cold. I have changed some things since then... so I will go back to the slow jet I had in at that time and the needle jet I had at that time and see if that helps. Any advice would be much appreciated!

Add a little more fuel to your idle circuit.
At what rpm do you have the idle set?

Nebr_Rex wrote: Add a little more fuel to your idle circuit.
At what rpm do you have the idle set?

Sorry for the late reply, couldn't get to the computer yesterday...With the choke on It starts out pretty high at about 3,000 then it drops to about 1000 and will continue to drop and stall unless I keep throttling it. When it's warm it idles at about 1,200. Which is within the specs the manual gives me. So it could possibly be just a pilot screw adjustment. I just got my carb sync tool.. so maybe I'll adjust the pilot screws again and then resync?

recez wrote:

Nebr_Rex wrote: Add a little more fuel to your idle circuit.
At what rpm do you have the idle set?

Sorry for the late reply, couldn't get to the computer yesterday...With the choke on It starts out pretty high at about 3,000 then it drops to about 1000 and will continue to drop and stall unless I keep throttling it. When it's warm it idles at about 1,200. Which is within the specs the manual gives me. So it could possibly be just a pilot screw adjustment. I just got my carb sync tool.. so maybe I'll adjust the pilot screws again and then resync?

Do you quit choking the engine when it drops to 1000 rpm ?
And does it idle normally then?
What are your current slow and needle jet? previous?

Maybe your enrichment circuit plungers are not returning or sealing properly.

Since you can start cold, you are getting fuel, but as it warms up, the mixture is too rich and the idle drops.

Blipping the throttle makes it richer for an instant, so that is why it dies.

When you turn the choke off, you are actually lowering plungers to shut off the enrichment circuit, The plungers are supposed to move down and seal. Check them out.

Nebr_Rex wrote:

recez wrote:

Nebr_Rex wrote: Add a little more fuel to your idle circuit.
At what rpm do you have the idle set?

Do you quit choking the engine when it drops to 1000 rpm ?
And does it idle normally then?
What are your current slow and needle jet? previous?

Thanks for the replys guys. If I quit choking when the engine drops to 1000rpm, It will stall without the choke on as well. Basically it will shut right off if I turn the choke off within the first 2 or 3 mins. It only idles normal after I've rode for a bout 5 or 10 mins and have reach full operating temp I guess. Maybe i need to check my enrichment circuit as loudhvx suggested. The slow jet and needle jet I switched to was the stock set that came in the carb when I got the bike. When I first had it running I used the carb rebuild kit slow and needle jets (which are the same size). The reason I switched back to the stock jets was because I read that the rebuild kit jets aren't made as well as the kawasaki ones, which made sense to me, so I switched back. Maybe I should have just left the new rebuild kit jets in there. They seemed to work good.. if not better than the stock. i think I read something on kz400.com that said the rebuild kits just weren't good and try sticking with as much stock parts as you can... not sure if thats the case at this point.

Sounds like your idle curcuit is partially clogged.