Evinrude 4906B 4HP 1969 Owner's Manual page 41

2-16 TUNING
bottom carefully for marine growth or evi-
dence of a "hook" or a "rocker"
bottom. Either one of these conditions will
greatly reduce performance.
Performance
Mount the motor on the boat. Install the
remote control cables and check for proper
ad justment.
Make an effort
what might be considered an average gross
load. The boat should ride on an even keel,
without a list to port or starboard.
the motor tilt angle, if necessary, to permit
the boat to ride slightly
stern. If heavy supplies are stowed aft of
Boat performance will
the bottom is damaged.
in the
to test the boat with
Adjust
higher than the
be drastically hampered,
the center,
boat will "plane" more efficiently.
test the boat must be operated in a body of
water.
Check the engine rpm at full throttle.
The rpm should be within the Specifications
in the Appendix.
ser ial number identification
the horsepower rating and rpm range for the
engine. If the rpm is not within specified
range, a propeller change may be in order.
A higher pitch propeller will decrease
and a lower pitch propeller
rpm.
For maximum low speed engine perform-
ance, the idle mixture
should be readjusted under actual operating
conditions.
if
Maximum engine performance
through proper tuning using
the bow will be light and the
All OMC engine model
plates indicate
will increase
and the idle rpm
can only
a
tachometer.
For this
rpm,
be obtained