I have a 07 WR450 that I have done the free mods to other than the grey wire thing, for my riding style and the type of riding I do it seems to work better with the grey wire hooked up. The bike runs great, plenty of power, and a smooth delivery. I have heard that the WRs run in a very lean condition, will that have any long term effects on the engine. I cant see any reason for rejetting as I like the performance unless it will harm the motor down the line. Thanks in advance.