Yanmar 6LY3 series Service Manual page 50

PERIODIC MAINTENANCE
2. Spray Pattern Inspection
Check the spray pattern. If the spray condition is
improper, have the nozzle cleaned at an
authorized FIE (Fuel Injection Equipment)
service shop or replace the nozzle.
Figure 4-18
Figure 4-18
3. Leak Test
Increase the pressure to near the specified
injection pressure of 0.98 to 1.96 MPa
(142-284 psi). Check for fuel leakage from the
injection hole and around the retaining nut. If
leakage occurs from the nozzle, replace, clean or
overhaul the nozzle. NOTICE: If disassembly of
the nozzle holder retaining nut is necessary,
have it done at an authorized FIE Service Center.
Figure 4-19
Figure 4-19
CAUTION! Never use a steel wire brush to clean
fuel injectors. Damage to the nozzle and other
components is likely to result.
4-18
Adjust Intake / Exhaust Valve Clearance
Take measurements and make adjustments while
the engine is cold.
1. Valve clearance measurement
(a) Remove the rocker arm cover.
(b) Turn the crankshaft in the direction of normal
0006175
Figure 4-20
0006176
© 2007 Yanmar Marine International
Periodic Maintenance Procedures
rotation to bring the piston of the No.1
cylinder to its compression top dead center
(TDC) while adjusting the index mark
(Figure 4-20, (2)) of the flywheel housing
(Figure 4-20, (1)) and the top mark of the
flywheel. (At compression TDC both intake
and exhaust valves are closed.) NOTICE:
The crankshaft should be turned clockwise
as seen from the water pump end. The No. 1
cylinder position is on the opposite side of
the drive shaft housing. Since there is a
clearance between the rocker arm and valve
bridge at compression, TDC can be checked
by hand. Also, see that the top mark on the
flywheel aligns with the index mark on the
flywheel housing. If there is no valve
clearance, disassemble and inspect the
valve seat area for abnormal or excessive
wear.
Figure 4-20
1 – Flywheel Housing
2 – Index Mark
6LY3 Service Manual
(1)
(2)
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