Mercury 25 EFI FourStroke User Manual page 65

2. Pull out the dipstick. Wipe it with a clean rag or towel and
push it back in all the way.
a
b
a - Full mark
b - Add mark
c - Dipstick
d - Oil fill cap
3. Pull the dipstick back out again and observe the oil level. Oil
must be between full mark and add mark. If the oil level is
low, remove the oil fill cap and fill to (but not over) the upper
oil level.
NOTE: Under certain conditions, the operating temperature of
4‑stroke outboard engines may not get hot enough to evaporate
the normal fuel and moisture that accumulate in the crankcase.
These conditions include operating at idle for long periods,
repeated short trips, slow speed or quick stop‑and‑go operation,
and operating in cooler climates. This additional fuel and
moisture that collects in the crankcase eventually ends up in the
oil sump and will add to the total volume of oil that appears on
the dipstick reading. This increase in oil volume is known as oil
dilution. Outboard engines can typically handle large amounts of
oil dilution without causing durability problems. However, to
ensure extended life of the outboard engine, Mercury
recommends that the oil and filter be changed regularly
following the oil change interval and using the recommended oil
quality. It is further recommended that if your outboard is
operated frequently in the conditions described above, that
more frequent oil change intervals be considered.
eng
FUEL AND OIL
c d
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