Evinrude 4906B 4HP 1969 Owner's Manual page 170

Checking Compression
4- Remove the
ALWAYS grasp the molded cap and pull it
loose with a twisting
damage to the connection.
spark plugs and keep them in
cylinder for evaluation
spark plug leads to the engine to render the
ignition system
performing the compression check.
Insert a compression
No.1, top, spark plug opening.
engine with the starter,
starter cord, through
piston strokes with the throttle
open position, or until
reading is observed on the gauge.
the reading.
Repea t the test and record the compres-
sion for each cylinder.
cylinders is far more important
actual readings. A variation of more than 5
psi between cylinders
compression cylinder may be defective.
problem may be worn, broken, or sticking
piston rings, scored pistons or worn cylin-
ders. These problems may only be deter-
mined after the head has been removed.
Removing the head on an outboard engine is
not that big a deal, and may save many
hours of frustration
purchasing unnecessary
faul ty condition.
Condenser
In simple terms, a condenser is composed
of two sheets of tin
spark plug wires.
motion to prevent
Remove the
ORDER by
later. Ground the
inoperative while
gauge into the
Crank the
or pull on the
at least 4- complete
at the wide-
the highest possible
Record
A variation between
than the
indicates the lower
The
and the cost of
parts to correct a
or aluminum foil laid
TROUBLESHOOTING
ALTERNATE LAYERS
-
INSULATION -- WAXED
ALTERNATE
\
to
Rough sketch illustrate
aluminum [oil, and insulation
condenser.
one on top of the other, but separated
sheet of insulating 'material
paper, etc. The sheets
cylinder to conserve space and then inserted
into a metal case for protection
permit easy assembly.
The purpose of the condenser is to ab-
sorb or store the secondary current built up
in the primary winding at the instant
breaker points are separated.
or stor ing this current,
vents excessive arcing and the useful life of
the breaker points is extended.
ser also gives added force
produced in the secondary
condenser discharges.
Modern condensers
lems, therefore, it is not necessary to install
a new one each time the points are replac-
ed. However, if the points show evidence of
arcing, the condenser
should be replaced.
not be detected without the use of special
test equipment. The modest cost of a new
condenser justifies its purchase and installa-
tion to eliminate this item as a source of
trouble.
Proper hookup
OF
PAPER
LAYERS OF FOIL
TI N OR ALUM I NUH
FOIL
INSULATION
how the waxed paper,
a
are rolled in typical
by a
such as waxed
are rolled into a
and to
the
By absorbing
the condenser pre-
The conden-
to the charge
winding as the
seldom cause prob-
may be at fault and
A faulty condenser may
to test a condenser.
5-11