MerCruiser 13, Service Manual

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MAINTENANCE - 1B - 9 90-816462 2-695
Coolant for Closed Cooling System
! CAUTION
Alcohol or Methanol base antifreeze or plain wa-
ter, are not recommended for use in fresh water
section of cooling system at any time.
We recommend that the coolant section of closed
cooling system be filled with Quicksilver Pre-Mixed
Engine Coolant. In areas where the possibility of
freezing does not exist, it is permissible to use a solu-
tion of rust inhibitor and water (mixed to manufactur-
er’s recommendations).
Maintaining Crankcase Oil
Level
Overfilled Engine Crankcase
Overfilled crankcases (oil level being too high ) can
cause a fluctuation or drop in oil pressure and rocker
arm “clatter” on MerCruiser engines. The over-full
condition results in the engine crankshaft splashing
and agitating the oil, causing it to foam (become aer-
ated). The aerated oil causes the hydraulic valve lift-
ers to “bleed down.” This, in turn, results in rocker arm
“clatter” and loss of engine performance, due to the
valves not opening properly.
Care must be taken when checking engine oil level.
Oil level must be maintained between the ADD mark
and the FULL mark on the dipstick. To ensure that you
are not getting a “false reading,” make sure the follow-
ing steps are done before checking the oil level.
•
Boat “at rest” in the water, or
•
If boat is on a trailer, raise or lower bow until the
boat is setting at the approximate angle that it
would be if setting “at rest” in the water.
•
Allow sufficient time for oil to drain into the crank-
case if engine has just been run or oil has just been
added.
Checking Engine Oil Level/Filling
IMPORTANT: ENGINE CRANKCASE OIL MUST
BE CHECKED AT INTERVALS SPECIFIED IN
“MAINTENANCE SCHEDULE” CHART. It is nor-
mal for an engine to use a certain amount of oil in
the process of lubrication and cooling of the en-
gine. The amount of oil consumption is greatly
dependent upon engine speed, with consump-
tion being highest at wide-open-throttle and de-
creasing substantially as engine speed is re-
duced.
1. Allow oil to drain back into oil pan - approximately
5 minutes.
2. Remove dipstick. Wipe clean and reinstall. Push
dipstick all the way into dipstick tube.
3. Remove dipstick and note the oil level.
4. Oil level must be between the FULL and ADD
marks.
5. If oil level is below ADD mark, proceed to Steps
6 and 7.
6. Remove oil filler cap from valve rocker arm cover.
7. Add required amount of oil to bring level up to, but
not over, the FULL mark on dipstick.
Changing Oil and Filter
1. Start engine and run until it reaches normal oper-
ating temperatures.
IMPORTANT: Change oil when engine is warm
from operation, as it flows more freely, carrying
away more impurities.
2. Stop engine.
3. Remove drain plug from oil pan or from oil drain
hose.
NOTE: If drain plug is not accessible because of boat
construction, oil may be removed through dipstick
tube, using a Quicksilver Crankcase Oil Pump.
4. After oil has drained completely, reinstall drain
plug (if removed) and tighten securely.
5. Remove and discard oil filter and its sealing ring.