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Kz440 high idle. Again.

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12 Nov 2020 11:33 #838387 by Terrorshark
Kz440 high idle. Again. was created by Terrorshark
So this is really stumping me and I’m hoping for some help.
Fully stock 81 kz440.
Carbs have been cleaned in an ultrasonic.
Diaphragms have no tears.
Main jet is 72. ( bike is at high altitude)
Pilot is 35.
Cable moves freely.
New intake boots.
Checked for leaks at intake boots with starter fluid and there is no change.
Carbs have been synced.
Advance on ignition moves freely.
Tappets in spec.
Plugs look great. A little dark but nothing crazy.

I’ve gone up on pilot and main jet and still have the same issue which makes me think there’s an air leak somewhere I just can’t find it. What am I overlooking.

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12 Nov 2020 15:19 #838390 by Nessism

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12 Nov 2020 16:58 #838397 by Terrorshark
Replied by Terrorshark on topic Kz440 high idle. Again.
I’ve tried from closed to all the way out. Doesn’t seem to do much actually. Just makes it smell super rich. But usually it’s 1.5 to 2.5 turns

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13 Nov 2020 05:19 #838419 by F64
Replied by F64 on topic Kz440 high idle. Again.
a leak in the vacuum petcock.
i guess you could verify by disconnecting the vacuum line from the petcock and capping the port on the carb.

81-KZ440-D2.
Louis Dudzik's GM HEI ignitor conversion installed 2015 s3.amazonaws.com/gpzweb/Ignition/GPZgmHEImod.html
Motogadget m-unit blue installed 2017.
LIC, NY

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13 Nov 2020 12:16 - 13 Nov 2020 13:55 #838439 by Terrorshark
Replied by Terrorshark on topic Kz440 high idle. Again.
I have both capped. Still idles high and will hang up very slow to come down. I also did notice that when the idle adjuster is all the way out it will return without a problem. I also notice that the left carb while synching rises much slower on the gauge.
Last edit: 13 Nov 2020 13:55 by Terrorshark.

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13 Nov 2020 14:17 #838445 by TexasKZ
Replied by TexasKZ on topic Kz440 high idle. Again.
If the engine runs with the idle adjustment screw all the way out, then there may be a problem with the way the carbs were initially set up. When bench synchronizing them before installation, the idle adjustment screw should be in the middle of its travel before setting the butterflies. That way you can adjust in either direction as needed.
At this point, it may be best to go back to the beginning and go through all of the setup to be sure everything is correct, including fuel levels, bench synch, cable adjustments, et cetera.

1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough

www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
The following user(s) said Thank You: Nessism

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22 Dec 2020 13:13 #840414 by gavroyer
Replied by gavroyer on topic Kz440 high idle. Again.
I know this is an old thread. One thing to check is the timing is dead on in spec with a timing light and that the coil throws a spark a good long way if you unscrew the plug boot and (carefully) hold the wire a centimetre or so from the head while briefly blipping the starter. If it can't throw a spark that distance, then the coil or one of your ignition components might be bad.

Overly advanced timing will definitely make the bike behave as if it's too lean, 40% of carb problems are ignition problems.

1980 KZ440-A1 LTD

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