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.
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.
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
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.