Honda BF8, BF9.9 and BF10 Outboard Motors Shop Manual., Page 173Get this manual
9) Support the cylinder head above the work bench surface to prevent possible valve damageTap the valve stems gently using two plastic hammers as shown to seat the cotters firmly10) Apply molybdenum oil solution to the camshaft journals and cam lobesInstall the camshaft with the key groove facing the rocker arm side as shownTake care not to damage the oil seal11) Lubricate the rocker arms and rocker arm shaft with molybdenum oil solution12) Make sure the valve adjusting screw and lock nuts are