grey oil in 400ex

[FJC50]

have 2001 400ex with white bros exhaust,k&n filter and jet kit. oil turns grey right after changing and minor smoking at high rpm. just got 440 big bore kit installed and adjusted valves, still grey oil. any ideas.

[GPracer2500]

Is the clutch slipping? Excessive clutch wear will turn oil grey.

[FJC50]

hope not, i have less than 10 hours on a new barnett clutch. last oil change i didn't ride it, just started and warmed up in place. still grey turned grey right away. could it be the valve seals?

[Trevor]

The only time i've seen oil go grey is when theres water in it. But the 400ex isn't liquid cooled is it?

[BigValvedEX]

How many times have you changed it since you rebuilt it,... did you do any bottom end work? The oil will be a little grayish the first and maybe second change after a rebuild due to the metal from the freshly honed cylinder wall and the rings are being seated wearing a little of that metal away.