2005 Yamaha F90TR 90HP Outboards Factory Service Manual, Page 98Get this manual
Cylinder head S69J5970
Cam lobe a: Intake: 36.4836.58 mm (1.43621.4402 in) Exhaust: 36.9037.06 mm (1.45281.4591 in) Cam lobe b: Intake: 29.9530.05 mm (1.17911.1831 in) Exhaust: 29.9230.08 mm (1.17801.1842 in) 2Measure the camshaft runoutReplace if above specification
Camshaft journal diameter c: 24.96024.980 mm (0.98270.9835 in) Camshaft cap inside diameter d: 25.00025.021 mm (0.98430.9851 in)
Checking the cylinder head
1Eliminate carbon deposits from the combustion chambers and check for deterioration2Check the cylinder head warpage using straightedge and thickness gauge in the directions shownReplace if above specification