1963-1973 Mercruiser all Engines and Drives Service Manual Books 1 and 2, Page 462Get this manual

1963-1973 Mercruiser all Engines and Drives Service Manual Books 1 and 2, Page 462

"iOT E: Th is }!I -turn preload adjustm ent must be don slowly to allow lifter to adjust itself, thus prev enting poss ibility
("Specifications", Section 8) between rocke arm and valve stem(4) Turn rocker rm nu down until li gh drag is felt on feeler
gauge Tbis is correct valve lash 4Va lve AdjustmentEngine Running (2) With engine running at idleback valve ro cke arm nuts
off (one at time) ntil valve rocker arm ta rts to latter(3) Turn rocker arm nut down until clatter just stopsThis is ze ro
lash position(4) Turn nut down additional turn and pause 10 seconds unti engine runs smoothlyRepeat addi tional turnspausing
10 sec-onds each timeuntil nut has been turned down li -turn from the ze ro lash pos ition NO TE: Care must be taken to dis
ting uish between intake valves and exhaust valves, as each requires different clearances(5) Repeat Steps 2, and to adjust