Hers's a plug question

Will 5000 rpm's usually clean your plugs to white? Not a frosty dry looking white just kinda clean without visable damage to any part of the plug. The plugs come out looking kinda new actually. Only time they get that brownish color is if I do idle for a like 5 minutes before cutting the engine. Also I tuned the carbs to get them just right at idle ( not to lean or rich) But when I am at higher rpm's I think it goes lean? Can a colortune be used to adjust the main jets? Should I have blocked off the YICS before tuning with Colortune? Everything is stock on this bike 82 xj750.

 

Sweeten the Mixture by moving the Pilot Mixture Screw Out ... 1~1.5 degrees.
Almost NOT moving it at all. Just a "Hair" or a half-a-hair!

If you are running "On the Lean Side" for rapid acceleration and sportiness to the Throttles ... the Mixture is Lean --> But not critically lean.

Running the Bike at High revolutions should cause and unusual coloration.
The Plug should look "Yellowed" and the Ground Electrode charcoal grayed.
The condition is called "High-Speed Glasing."

Normally, you don't get Glasing until you are right up in the top of the Power Band for a good while ... or, the Bike's' running real good and you are lighting your hair on fire and pretending to be just a few lengths behind the leader all day long!

Keep an eye on those Plugs.
Use a magnifying glass.
Erosion or hairline fracturing of the Plug's Center Electrode means you have to either give it some more supplemental gas from the Pilots or go to the Next size Main Jet.

Apparently, you have it running pretty good.
That's always nice.

Don't get addicted to the way the Air Cooled Engine likes to run lean.
You start looking for a little more power out of the hole and you'll get that thing too lean and put a hole right through the top of a Piston.