MAINTENANCE
SERVICE MANUAL NUMBER 25
90-861328--1 NOVEMBER 1999
Page 1B-7
20-Hour Break-In Period
IMPORTANT: The first 20 hours of operation is the engine break-in period. Correct
break-in is essential to obtain minimum oil consumption and maximum engine per-
formance. During this break-in period, the following rules must be observed:
•
Do not operate below 1500 rpm for extended periods of time for first 10 hours. Shift into
gear as soon as possible after starting and advance throttle above 1500 rpm if condi-
tions permit safe operation.
•
Do not operate at one speed consistently for extended periods.
•
Do not exceed 3/4 throttle during first 10 hours. During next 10 hours, occasional opera-
tion at full throttle is permissible (5 minutes at a time maximum).
•
Avoid full throttle acceleration from IDLE speed.
•
Do not operate at full throttle until engine reaches normal operating temperature.
After Break-in Period
To help extend the life of your Mercury MerCruiser power package, the following recommen-
dations should be considered:
•
Use a propeller that allows the engine to operate at or near the top of the maximum rpm
range (refer to “Specifications” section) when at full throttle with a normal boat load.
•
Operation at 3/4 throttle setting or lower is recommended. Refrain from prolonged op-
eration at maximum (full throttle) rpm.
End of First Season Checkup
At the end of the first season of operation, an Authorized Mercury MerCruiser Dealer should
be contacted to discuss and/or perform various scheduled maintenance items. If you are
in an area where the product is operated continuously (year-round operation), you should
contact your dealer at the end of the first 100 hours of operation, or once yearly, whichever
occurs first.