Yanmar 6LY3 series Service Manual page 52

PERIODIC MAINTENANCE
(c) Tighten the bridge adjusting bolt gradually
while moving the thickness gauge, and
confirm the position where the movement of
the thickness gauge becomes tight (the
position where the adjusting bolt touches the
valve top). Then tighten the bridge adjusting
bolt 45° and lock the bolt with the locknut.
Figure 4-23
Figure 4-23
(d) Loosen the rocker arm adjusting bolt and
readjust the valve clearance by using the
rocker arm adjusting bolt. NOTICE: If the
valve bridge has not been replaced or
moved to another cylinder, the above steps
(a, b, and c) are not necessary.
Standard Valve Clearance
Intake Valve
Exhaust Valve
4-20
0006180
0.15-0.25 mm
(0.0059-0.0098 in.)
0.45-0.55 mm
(0.0177-0.0216 in.)
© 2007 Yanmar Marine International
Periodic Maintenance Procedures
(e) Apply oil to both sides (valve and push rod,
contact surface) of rocker arm.
(f) Adjusting Other Cylinders
Turn the crankshaft 120° and adjust the No.
4 cylinder. Then adjust the No. 2 cylinder in
the normal firing order. The cylinder to be
adjusted first does not have to be the No. 1
cylinder. Select and adjust the cylinder
nearest to top dead center (TDC) and adjust
other cylinders in the firing order of the
engine by turning the crankshaft 120° each
time.
Drain the Fuel Tank
Open the drain cock of the fuel tank. Inspect for
water, dirt or other sediment. Drain (water, debris,
etc.) from the tank's bottom. Catch the fuel in an
approved container. Drain until clean fuel flows and
then close the drain cock.
Replace the Fuel Filter Element
When the engine is operated on light diesel fuel,
replace the fuel filter element every 250 hours or
1 year of operation.
1. Close the fuel cock on the fuel tank.
2. Remove the center bolt (Figure 4-24, (10)) at
the bottom of the filter and take out the filter
element (Figure 4-24, (3)).
3. Replace the element, reinstall the bolt and
tighten.
4. Bleed air from the fuel filter system.
6LY3 Service Manual