Yanmar 6LY3-STC Operation Manual page 65

Clean the Exhaust / Water Mixing
Elbow
The mixing elbow is attached to the
turbocharger. The exhaust gas is mixed with
seawater in the mixing elbow.
1. Clean dirt and scale out of the exhaust
gas passage and seawater way in the
mixing elbow.
2. Repair the crack or damage of the mixing
elbow by welding, or replace if
necessary.
3. Inspect the gasket and replace if
necessary.
Clean the Turbocharger Blower
Contamination of the turbocharger blower
causes blower revolutions to drop and
engine output to fall.
If a drop of engine output is noted (by about
10%), clean the blower. This should only be
done by a trained and qualified technician.
See your authorized Yanmar Marine dealer
or distributor to clean the turbocharger
blower.
Flush the Aftercooler
Contamination of the aftercooler causes the
engine output to fall.
If a drop of engine output is noted (by about
10%), flush and clean the aftercooler.
This should be done only by a trained and
qualified technician. See your authorized
Yanmar Marine dealer or distributor to flush
the aftercooler.
Check the Wiring Connectors
Check for any loose connections.
Tighten All Major Nuts and Bolts
After a long period of usage, the major nuts
and bolts of the engine may loosen. Tighten
the major nuts and bolts to the standard
tightening torques. This inspection requires
specialized knowledge and techniques. See
your authorized Yanmar Marine dealer or
distributor to tighten major nuts and bolts.
6LY3 LDC Operation Manual
Check / Replace the Flexible Engine
Mounts
The rubber tension of the flexible engine
mounts is lost after many hours of use.
This leads to a drop in vibration absorption
performance, and also causes centering
misalignment of the propeller shaft.
1. Check if the rubber is cracked. If
necessary, replace the flexible mount.
2. Check for abnormal noise or vibration
while engine is running. If necessary,
replace the flexible mount.
CAUTION! NEVER get any engine oil or
diesel fuel oil on the flexible rubber
mount. Oil makes rubber deteriorate.
Replace Engine Coolant
CAUTION! Wear eye protection and
rubber gloves when you handle engine
coolant. If contact with the eyes or skin
should occur, flush eyes and wash
immediately with clean water.
Cooling performance drops when coolant is
contaminated with rust and scale. The
coolant must be replaced periodically
because its properties deteriorate over time.
To drain the engine coolant, open the
freshwater drain cocks (two places).
See Engine Coolant on page 29 for coolant
specifications.
NOTICE: NEVER mix different types and /
or colors of coolants.
Discard old coolant in an approved manner
according to environmental laws.
© 2008 Yanmar Marine International
PERIODIC MAINTENANCE
59