How much load and throttle needed to check plug coloration?

[Rema1000]

I've read that to get a good indication of main jetting, I should run the bike for a couple of minutes at WOT, under load (like up a slight hill), and then grab the clutch and hit the kill switch, pull over and check plug color.  But if I run WOT for "a few minutes," then I'll either be doing 100mph, or else I'll be down in 4th gear, where the engine won't be under much load.

Then again, I read somewhere else that you can just run WOT in neutral, and the engine doesn't need to be under load at all :dunno:

So: how much throttle do I have to give before getting a good look at plug color for the mains?  3/4 throttle?  WOT?  And how much load needs to be on the engine (is WOT in 4th gear OK?  or WOT in neutral?).  And how long do I need to sustain that speed to get coloration on the plug (5 seconds? 2 minutes?)

[dgyver]

Your actual speed or rpm is not important. You can ride about 45 in 6th gear at WOT and then kill the motor. 10 seconds should be plenty. The engine will bog down enough and you will not accellerate that much. Running in neutral at WOT will not work.