Idle Problem

I have a 1976 KZ900 with Mukuni 29's. I have a problem when starting the bike. I have to turn the idle screw in to keep the bike running or twist the throttle. The choke is not working. After the bike warms up, I have to turn the idle screw back our to get the idle to come back down. Anyone have any suggestions on how/fix the choke issue ?

Anyone have any ideas ? I will be pulling the carbs back off tomorrow to check things again.

Would pay close attention to cleaning the starter (enrichener) circuit in each carb, and also assure the choke plungers are all opening and closing simultaneously.

Spray plenty of carb cleaner through the "open" choke circuit (plungers "up" in normal running position), and assure the cleaner is exiting into the carb bore.

Good Fortune!

Thanks Patton for the reply. I am new to carbs so some of my question may not be very good. Exactly how do I check the starter circuit ? I have had the carb apart before. How do you check to see if the plungers are opening and closing simulataneously ? Where is the "open" chock circuit located ?

Make sure to dissasemble the carbs completely before using any cleaners in there.

The choke plungers are the parts that move in and out of the carb bodies as you adjust the choke.
With the carbs off the bike. look at them and move the choke. You will see it moving all the little choke plungers up/down as it should - or maybe something is broken...

They can be easily screwed out of the carbs for inspection/cleaning.

the most important thing to when cleaning the carbs is to spray cleaner through the pilot hole in the bottom of the carb, and watch for it to squirt out all the tiny little holes in the carb bore.

This will assure you that the pilot circuits are clear and you wont have to dissasemble them again later not being sure that they are clean.

Good luck.



Choke pic:

I had the carbs off earlier today and the plungers are moving in and out of the carb bodies at the same time. I did not know that you could screw them out. I'll take the carbs back off tomorrow. What do they look like when you take them out ?

I'll pull them out tomorrow and make sure they are clean.

Typical carb starter (aka choke aka enrichener) circuit:



Good Fortune!

just a reminder when SPRAYING carb cleaner wear SAFTY GLASSES
that stuff will back fire in your face quicker than you can say Howdy Dudy.

I didn't get a chance to check them yesterday, but hopefully I'll get a chance tomorrow. After it warms up, it idles good. Thanks for all of the help.

Is the starter pipe the thin copper pipe that goes into the bowl ?