Cautions During Operation - Yanmar 3JH5E Operation Manual

CAUTIONS DURING
OPERATION
NOTICE: Engine trouble can arise if the
engine is operated for a long time under
overloaded conditions with the control lever
in the full throttle position (maximum engine
speed position), exceeding the continuous
rated output engine speed. Operate the
engine at about 100 rpm lower than the full
throttle engine speed.
Note: If the engine is in the first 50 hours of
operation, see New Engine Break-In on
page 16.
Always be on the lookout for problems
during engine operation.
Pay particular attention to the following:
• Is sufficient seawater being discharged
from the exhaust and seawater outlet
pipe?
If the discharge is small, stop the engine
immediately; identify the cause and repair.
• Is the exhaust color normal?
The continuous emission of black exhaust
smoke indicates engine overloading. This
shortens the engineʼs life and should be
avoided.
• Are there abnormal vibrations or noise?
NOTICE: Excessive vibration may cause
damage to the engine, marine gear, hull
and onboard equipment. In addition, it
causes noticeable passenger and crew
discomfort.
Depending on the hull structure, engine
and hull resonance may suddenly become
great at a certain engine speed range,
causing heavy vibrations. Avoid operation
in this speed range. If you hear any
abnormal sounds, stop the engine and
inspect.
JH Series Operation Manual
• Alarm buzzer sounds during operation.
NOTICE: If any alarm indicator with
audible alarm sound appears on the
display during engine operation, stop the
engine immediately. Determine the cause
and repair the problem before you
continue to operate the engine.
• Is there water, oil or fuel leakage, or are
there any loose bolts?
Check the engine room periodically for any
problems.
• Is there sufficient diesel fuel in the diesel
fuel tank?
Replenish diesel fuel before leaving the
dock to avoid running out of fuel during
operation.
• When operating the engine at low speed
for long periods of time, race the engine
once every 2 hours.
NOTICE: Racing the engine: With the gear
in NEUTRAL, accelerate from the low-
speed position to the high-speed position
and repeat this process about five times.
This is done to clean out carbon from the
cylinders and the fuel injection valve.
Neglecting to race the engine will result in
poor exhaust color and reduce engine
performance.
• If possible, periodically operate the engine
at near maximum rpm while underway.
This will generate higher exhaust
temperatures, which will help clean out
hard carbon deposits, maintaining engine
performance and prolonging the life of the
engine. NOTICE: NEVER turn off the
battery switch (if equipped) or short the
battery cables during operation. Damage
to the electric system will result.
© 2009 Yanmar Marine International
ENGINE OPERATION
51