1999 Volvo Penta "WT" Models Workshop Manual, Page 184Get this manual
3With engine assembly in number cylinder firing position, following valves can be adjusted: Exhaust 1, 3, 4, Intake 1,2,5,7
4Back off valve rocker arm nut until lash is felt in valve push rodThen tighten valve rocker arm nut until all lash is removedZero lash can be felt by moving valve push rod up and down between thumb and forefinger until there is no more movement5When all free play has been removed, tighten valve rocker arm nut one additional turn (360 degrees)6Turn crankshaft one revolution until hub arrow is again at 12 o'clock positionThis is number cylinder firing positionFollowing valves can now be adjusted: Exhaust 2, 5, 6, Intake 3, 4, 68