[Hardtailchop]

Hav you been running this motor for awhile with out this issue or did it just start happening? I would make sure that your crank case vent line is clear and that oil is returning to your oil tank through your return line properly. I have also seen this problem occur once when the later twin cam oil filter is use on an evo. the oil pressure backs up and wont flow correctly thru the higher micron filter.