TOPIC:

Good morning everyone.

I am struggling to get the carburetion on my 1977 KZ650B1 right. I have ditched the stock airbox and have single pod filters.

Now... I have it running, idling and can drive it no problem. It will do highway speed easily, pulls clean from a start and doesn't buck or shudder on acceleration or when I let off the throttle. But the spark plugs still keep getting dark and sooty after 100 or so miles. I have gone from 100 main jets to 105 mains. I have #15 pilot jets in. The needle is in the stock position.

The trouble seems to be in the adjustment of the air screws. My Clymer and Kawasaki manuals say the air screws for a stock setup should be at 1 1/8 turns out from seated. If I am adding air by switching to pods rather than the stock airbox, do I need less turnout on the air screws? Or more? I checked last night they are currently all set at 1 1/2 turns, a little higher than stock. I welcome some insight on this.

Thanks all...

Post edited by: barquirt, at: 2007/01/27 10:32

1 1/2 should be good
did you oil your k/n style filters?
as this helps reduce airflow and should
lean the mixture.

i found this site very helpfull.

www.dansmc.com/sparkplugs1.htm

I'm sure that others with 650s and K&Ns will chime in and help suggest jet sizes and needle clip positions and it will probably turn out to be carb or jet size issue but I gotta ask - did your plugs tend toward the sooty side before you made the mods ? If so then maybe check out the wiredgeorge coil modification at wgcarbs.com/59021.html

Often in older bikes the coils dont get the voltage they should, resulting in a weaker than optimum spark and sooty or fouling plugs. Check it out. A lot of people here have done this simple mod - including me - and will swear by it.

Post edited by: JR, at: 2007/01/27 10:58