Yanmar 6LY3 series Service Manual page 51

Periodic Maintenance Procedures
12/05
(c) Insert a thickness gauge between the
rocker arm and the valve bridge, and
record the measured valve clearance
(Figure 4-21, (1)). (Use this data to estimate
the state of wear.)
Figure 4-21
(1)
Figure 4-21
1 – Valve Clearance
(d) Measuring Other Cylinders
Turn the crankshaft 120° and make
adjustment for the No. 4 cylinder. Then
adjust the No. 2 cylinder according to the
firing order of the engine. The cylinder to be
adjusted first does not have to be the No. 1
cylinder. Select and adjust the cylinder with
the piston nearest to top dead center (TDC)
and make adjustments to other cylinders in
the order of ignition by turning the crankshaft
120° each time. NOTICE: Firing Order is
1-4-2-6-3-5.
6LY3 Service Manual
2. Valve Clearance Adjustment
(a) Loosen the adjusting bolt of the valve bridge
Figure 4-22
0006178
1 – Valve Bridge Adjusting Bolt
2 – Rocker Arm Adjusting Bolt
(b) Measure valve clearance temporarily. Insert
© 2007 Yanmar Marine International
PERIODIC MAINTENANCE
(Figure 4-22, (1)). Loosen the locknut of the
valve bridge adjusting bolt more than one
turn to give clearance between the adjusting
bolt and valve. Check the valve for any
inclination of valve cap or wear.
(1)
Figure 4-22
a thickness gauge between the rocker arm
and the valve bridge, and adjust the valve
clearance by using the rocker arm adjusting
bolt (Figure 4-22, (2)). Do not adjust the
bridge adjusting bolt. Tighten the rocker arm
adjusting bolt lightly (temporarily).
Standard Valve Clearance
Intake valve
(0.0059-0.0098 in.)
Exhaust valve
(0.0177-0.0216 in.)
(2)
0006179
0.15-0.25 mm
0.45-0.55 mm
4-19