2006-2012 Honda TRX90 TRX90EX/X Service Manual, Page 103Get this manual
CYLINDER HEADVALVES Loosen the valve adjusting lock nuts and screws fully to make valve clearance maximum (page 3-8)Temporarily install the cam sprocket bolts onto the camshaft, then remove the camshaft from the cylinder head
INSPECTION
Turn the outer race of the each camshaft beari ng with your fingerThe outer race should turn smoothly and quietlyAlso check that the bea ring inner race fits tightly on the camshaftReplace the camshaft assembly if the outer race does not turn smoothly and quietly, or if inner race fits loosely on the camshaft