black sooty plugs

I have a 1978 KZ1000 ltd with 15,000 mi on it,when i bought it the carbs were all gummed up,i'm a pretty good wrench and i did every thing right in my book but am haveing trouble with the plugs black with soot after only about 3 miles.Here is what i have; stock carbs with stock pipes that ahave no baffles(i like noise)120 main jets, 15 pilot jets, stock needles on the middle notch,all carbs cleaned, bead blasted exteriors, floats set to specs,all passages seem clean and clear!! Did the add a relay to the coil system for full power to the coils, new NGK resistor type plug wire ends,compression test 95-105lbs accross the board. # 1,2&4 are sooting and #3 is perfect, all settings on the carbs seem equal. What the heck am i doing wrong???If any one has an idea i'll be glad to listen. THANKS JEFF
Please note: Although no board code and smiley buttons are shown, they are still usable.

Sooting means incomplete burning which can come from an excessively rich carb setting, poor ignition spark, ot just poor combustion in general. 95-105 compression sounds like a very sick engine, which could account for the incomplete burning. Is that the reading with the throttle wide open when cranking?

How's the spark look? The sparkplug ignition leads must be tight going to the coils. Have you checked to see if the primary(smaller wires) are clean and tight?

How are the ignition coils? have you check the primary side with an ohm meter? I believe they should read about 2.2 to 3 ohms. Is the ignition electronic or do you have points?

An upgrade would be to purchase a Dyna "S" electronic ignition. www.z1enterprises.com can get one for you.

Thanks for responding, the comp. with the throttle wide open was 145-150 accross the board.

thanks for responding, the wires are tight and clean, brand new dyna S ign., have not checked the ohms but am getting 12.5 V to the coils.

jeffff wrote:

Thanks for responding, the comp. with the throttle wide open was 145-150 accross the board.

That sounds pretty good.

jeffff wrote:

I have a 1978 KZ1000 ltd with 15,000 mi on it,when i bought it the carbs were all gummed up,i'm a pretty good wrench and i did every thing right in my book but am haveing trouble with the plugs black with soot after only about 3 miles.Here is what i have; stock carbs with stock pipes that ahave no baffles(i like noise)120 main jets,

That sounds like big mains for a stock pipe setup. I looked up a 1978 KZ1000 on babbitts, and they show main jet sizes 102.5 -107.5. It shows a #110 labeled for racing only. #120 main jets sound like they are pretty big?

If you are running a stock air box then downsize the jets.
You are getting enough power to the coils so WG mod wont have much effect.

I had the same problem and a new battery did wonders for me.