After The 20-Hour Break-In Period; End Of First Season Checkup - Mercury 4.2 Diesel Operation & Maintenance Manual

Section 2 - On the Water
• Do not operate below 1500 RPM for extended periods of time for the first 10 hours. Shift into gear as soon as possible after
starting, and advance the throttle above 1500 RPM if conditions permit safe operation.
• Do not operate at one constant speed for extended periods.
• Do not exceed 3/4 throttle during the first 10 hours. During the next 10 hours, occasional operation at full throttle is
permissible (five minutes at a time maximum).
• Avoid full‑throttle acceleration from idle speed.
• Do not operate at full throttle until the engine reaches normal operating temperature.
• Check the engine oil level frequently. Add oil as needed. High oil consumption is normal during the break‑in period.

After the 20-Hour Break-In Period

To help extend the life of your power package, Mercury Marine recommends the following:
•
Change the engine oil and filter and the transmission fluid at the interval indicated in the Maintenance Schedule. Refer to
Specifications and Maintenance.
• Use a propeller that allows the engine to operate at the rated engine RPM when at full throttle with a fully loaded boat.
Refer to Specifications and Maintenance.
• Operation at 3/4 throttle setting or lower is recommended. Refrain from prolonged operation at wide‑open throttle RPM.

End of First Season Checkup

At the end of the first season of operation, contact an authorized repair facility to discuss or perform scheduled maintenance
items. If you are in an area where the product is operated continuously, year‑round, you should contact your dealer at the end
of the first 100 hours of operation or once yearly, whichever occurs first.
Page 24 90-8M0113988 DECEMBER 2015
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