Yanmar 6LY3 series Service Manual page 308

TROUBLESHOOTING
Trouble symptom
White exhaust smoke from warm engine.
Faulty fuel injection nozzle.
Improper fuel.
Excessive amount of oil in
the engine causing oil to
burn.
Insufficient amount of oil in
the engine causing oil to
burn.
13-18
Causes
Faulty valve and / or seat.
Sticking needle valve.
Wear of the seat.
Clogged fuel injection
hole(s).
Decrease in fuel opening
pressure.
Low cetane number.
Excessive aromatics in the
fuel.
Seized piston.
Wear of the piston rings.
Sticking piston rings.
Scarring or wear of the
cylinder wall.
Scarring or wear of the
intake / exhaust valves.
Scarring or wear of the valve
guides.
Damaged stem seal.
© 2007 Yanmar Marine International
Troubleshooting by Symptom
Corrective action
Check the fuel spray
condition with a tester. If a
malfunction is found, send to
an FIE shop for service or
replacement.
Replace fuel.
Replace fuel.
Disassemble and check.
Replace if necessary.
Check and replace.
Check, clean and replace.
Disassemble and check.
Repair or replace if
necessary.
Disassemble, check and
measure the dimension.
Repair or replace if
necessary.
Disassemble, check and
measure the dimension.
Repair or replace if
necessary.
Replace if necessary.
6LY3 Service Manual
Remarks
See Fuel Injection Nozzle
Components and Functions
on page 6-26.
See Fuel Selection on
page 3-6.
See Fuel Selection on
page 3-6.
See Inspecting the Pistons
and Piston Pins on
page 5-36.
See Measuring the Pistons
on page 5-37.
See Measuring the Pistons
on page 5-37.
See Inspecting the Cylinder
Block and Components on
page 5-22.
See Inspecting Intake /
Exhaust Valves and Valve
Guides on page 5-30.
See Inspecting Intake /
Exhaust Valves and Valve
Guides on page 5-30.
See Inspecting the Valve
Stem Seals on page 5-32.