[VelociRaptor]

Checking the spark plug in actual reality is part science and part art. Takes a keen eye to tune properly solely on sparkplug reading but this is what my plug looked like after a proper dyno tuning and racing one MX race with it:

 

[VelociRaptor]

This is the tune that it had(this was the difference between the HCII and HCIII camshafts in my build):

 

[scuzz]

To my novice eye that appears rich.

 

[VelociRaptor]

Its a touch rich because I like to tune the 700 Raptors rich down low because it brings on that large rise in torque between 4000-5000rpm. If I lean it out past 13:1 it goes away. When you ride it with it and without it its very noticeable especially while wheelieing, doesnt come up as fast. This will be something the XX guys will have to play with to see what the XX likes. I like to cross the 13:1 point in the rpm range at 2000rpm before peak hp.

 

[5W0P3]

Mine is DEFINITELY lean. The tip is almost whitish, not black like yours.

 

[VelociRaptor]

Well, maybe. The burn characteristics of the Honda chamber maybe leaner than the Yamaha, need to get it on a wideband O2 to make sure but it probably is lean with it being whiteish. Did it idle better yesterday?

 

[scuzz]

I bet mine is very white after yesterday, the stock map and the UNI filter.