My 89 XR600 has been down for two years now and I am ready to go riding again. I tore everything down a while back and had the cylinder bored, new piston, new rocker arms, 3 angle valve job, new stainless valves, new barnum's grind cam. My problem is, when I installed the cam, I lined the lines on the sprocket up parallel with the top of the cylinder head when the T mark on the rotor was lined up the notch on the side case. The problem is that the piston is not at top dead center when the rotor says it should be. When the piston is at TDC, the II mark shows up through the viewing window instead of the I T . What did I do wrong? Don't know if it matters, but the previous owner installed a niks pro-x rod.