2003 Arctic Cat ATVs from 250cc to 500cc Service Manual, Page 326Get this manual
2Acce,etable inside .diameter range is 12.000-12.018 mm (0.472-0.473 mMeasuring Rocker Arm Shaft (Outside Diameter)
1Using micrometer, measure the outside diameter of the rocker arm shaft
2Acceptable outside diameter range 11.973-11.984 mm (0.4714-0.4718 inInstalling Valves
2Insert an intake valve seat pilot shaft into one of the intake valve gUidesSlide the intake valve seat grinding tool onto the pilot shaft; then using light pressure on driver handle and deep socket, grind the intake valve seat until within specifications NOTE: Repeat procedure on the remaining intake valve
1Apply grease to the inside surface of the valve seals; then place lower spring seat and valve gUide seal over each valve gUide
2Insert each valve into its original valve location3Install the valve springs with the painted end of the spring facing away from the cylinder head NOTE: If the painted end is not visible, install the ends of the springs with the closest coils toward the head