Yanmar 6LY3-STC Operation Manual page 16

PRODUCT OVERVIEW
During the first 10 hours of operation, the
engine should be run at maximum rpm
minus 400 - 500 rpm (approximately
60 - 70% of load) most of the time. This will
ensure the sliding parts break in properly.
During this period, avoid operating at
maximum engine speed and load to avoid
damaging or scoring sliding parts.
NOTICE: Do not operate at WOT (wide open
throttle) for more than a minute at a time
during the first 10 hours of operation.
Do not operate the engine at low idle or at
low speed and light load for more than
30 minutes at a time. Since unburned fuel
and engine oil will adhere to the piston rings
when operating at low speeds for long
periods, this will interfere with proper
movement of the rings and the lube oil
consumption may increase. Low idle speed
does not allow break-in of sliding parts.
If operating engine at low speed and light
load, you must race the engine to clean the
carbon from the cylinders and fuel injection
valve.
10
Perform this procedure in open waters:
• With the clutch in NEUTRAL, accelerate
from the low speed position to the high
speed position briefly.
• Repeat this process five times.
Once past the initial 10 hours until 50 hours,
the engine should be used over its full
operating range, with special emphasis on
running at relatively high power settings.
This is not the time for an extended cruise at
idle or low speed. The boat should be run at
maximum speed minus 400 rpm most of the
time (approximately 70% load), with a 10
minute run at maximum minus 200 - 300 rpm
(approximately 80% load) every 30 minutes
and a 4 - 5 minute period of operation at
WOT (wide open throttle) once each 30
minutes. During this period, be sure not to
operate your engine at low speed and light
load for more than 30 minutes. If operating
engine at low speed and light load by
necessity, just after the low idle operation,
be sure to race the engine.
To complete engine break-in, perform After
Initial 50 Hours maintenance procedures.
See Periodic Maintenance Schedule on
page 47.
6LY3 LDC Operation Manual
© 2008 Yanmar Marine International