The spark that is visible is the atmospheric gasses ionizing and turning into a plasma conduit. The color and width of the spark is rather dependent on the composition of the atmosphere where you are, the humidity, and any impurities found in the air at your locale.
I'd say a blue-white spark is good and be wary of a yellow-orange one.
Do examine the plug wire end where it screws onto the boot post. If it is clean and tight, and you can see the wire center is in good condition and making good contact with the post screw, reassemble and move on to other issues. If the end looks bored out or there is goo on the mating interface, then you have had poor contact there and the arcing has caused the insulation to break down. Remove as much off the end of the wire to get to good solid wire and insulation, then screw the boot back on tightly.
For reading plugs you might look at :
http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.htmlThe outer base ring should always become black with use in these engines. The cylinder head mass is wicking away heat from the combustion chamber and the close contact with the plug means the fuel deposits can't maintain burn-off temps at the base ring. The center electrode insulator is the key. White usually means no deposits and a very hot, probably lean, mixture. Be wary of this as if you see signs of melted electrode metal, you are getting close to destructive detonation, and the aluminum pistons melt at a lower temperature than steel. Tan is a good color and you should see a gradient darkening of deposits on the insulator as you move away from the electrode tip down into the recess of the plug body. The bottom of the spark plug insulator well should be nearly as dark with carbon as the base ring, as the flame front will cool as it nears the outer boundaries of the combustion chamber.
Since your spark plug appearance is different on cylinder two, I will ask if the carbs have been vacuum synched. It is an interesting observation #2 is the only slide not adjustable. The other cylinder's carbs do have synchronizing adjustments for the slides.
Before you synchronize carbs, do check your valve tappet clearances and cam chain tension.
Points condition and gap is also on the list of to-check items.
Did you tell us about your exhaust? Stock? Non-stock and foam air filter may make this bike run too lean. You may have to go up a main jet size and shim the slide needle to richen up the midrange throttle settings. Partial choke may help with midrange throttle mixtures. But, the blocking of the intakes with the choke butterfly will reduce WOT power. Any chance you could try a paper filter element? A dirty one especially, should make the entire throttle range richer, including WOT. These would be diagnostic tools to give you confidence about Carb adjustments for the intake and exhaust components you've chosen.
The condensers role is to help reduce point contact arcing and pitting. How do the points look?
Cheers,
