Evinrude 4906B 4HP 1969, Руководство пользователя

Страница: 30 / 422

Worn ignition points are
a
common problem area
contributing to poor engine performance.
Breaker Points
Rough or discolored contact surfaces is
sufficient reason for replacement. The cam
follower will usually have worn away by the
time the points have become unsatisfactory
for efficient service.
Check the resistance across the con-
tacts. If the test indicates
ZERO
resis-
tance, the points are serviceable. A slight
resistance across the points will affect idle
operation. A high resistance may cause the
ignition system to malfunction and loss of
spark. Therefore, if any resistance across
the points is indicated, the point set should
be replaced.
2-6 SYNCHRONIZING
The timing on small OMC (Johnson and
Evinr ude) outboard engines is controlled
through adjustment of the points. If the
points are adjusted too closely, the spark
The fuel and ignition systems on any engine MUST
be properly synchronized before maximum performance
can be obtained from the unit.
IGNITION SYSTEM 2-5
plugs
will
fire early; if adjusted with exces-
sive gap, the plugs
will
fire too late, for
efficient operation. Therefore, correct
point adjustment and synchronization are
essential for proper engine operation. An
engine may be in apparent excellent me-
chanical condition, but perform poorly, un-
less the points and synchronization have
been adjusted precisely, according to the
Specifications in the Appendix. To synchro-
nize the engine, see Chapter 5.
2-7 BATTERY SERVICE
Many owner/operators are not fully
aware of the role a battery performs with a
magneto ignition system outboard engine.
To clarify: With a magneto ignition system,
a battery is only used to crank the engine
for starting purposes. Once the engine is
running properly, the battery could very
well be removed without affecting engine
operation. Therefore, if the battery is com-
pletely dead, the engine may be hand start-
ed with a pull cord and operate efficiently.
If a battery is used for starting, inspect
and service the battery, cables and connec-
tions. Check for signs of corrosion. Inspect
the battery case for cracks or bulges, dirt,
acid, and electrolyte leakage. Check the
electrolyte level in each cell.
Fill each cell to the proper level with
distilled water or water passed thru a de-
mineralizer.
The battery MUST be located near the engine in a
well-ventilated area. It must be secured in such a
manner that absolutely no movement is possible in any
direction under the most violent action of the boat.