Join Date: Apr 2009
Location: Gloucester, Va, USA
The bikes do come from the factory a little lean. The color of your plug may be the result of a hot plug more so than a lean tune. (not that a rejet is a bad idea, especially with your exhaust)
Some people have been led to believe that a hotter plug means more power, or even a stronger spark. Not the case.
The hotter a plug is, the better it cleans itself. If the plug is too hot, it will cause preignition. If the plug is too cold, it will foul easier. A healthy engine, with a good tune, will run fine with a cooler plug. If the engine is tuned rich (this may be the case for you, depending on the size jet you go with), a hotter plug may be required.
Either way, let us know how it works!