Yanmar ViO45-5 ViO45-5B ViO55-5 ViO55-5B Excavator Shop Manual

Description

ADJUSTING THE VALVE CLEARANCE
Make measurement and adjustment hole the engine is cold.
(a) Valve clearance measurement
1. Remove the rocker arm cover above cylinder head.
2. Set the no 1 cylinder in the compression TDC
Turn the crankshaft to bring the piston of the No.1 cylinder to its compression top dead center while
the rocker arm motion, timing scale and the top mark position of the crankshaft pulley.
NOTES;
1. The crankshaft shall be turned clockwise as seen from the radiator side
2. The No 1 cylinder position is on the opposite side of the radiator and the ignition order shall 1-3-4-2-1 at 180dgree intervals.
3. Since the intake and exhaust valve rocker arms are operated the same and there is a clearance between the arm and valve generally at the top dead center, the position can be checked by means of the play when
the arm head is held with a hand. Also see that the crankshaft pulley top mark is positioned at zero on the timing scale. If there is no valve clearance inspection in the disassembled state is necessary since the valve seat may be worn abnormally.