Mariner Mercury 105/140 JET, Service Manual

Page: 108 / 797

2C-6 - ELECTRICAL 90-824052R3 JUNE 2002
PRIMARY PICKUP TIMING ADJUSTMENT
1.
With engine in neutral, hold throttle arm so that
idle stop screw (a) is against idle stop. Crank en-
gine with starter motor and adjust throttle primary
pickup screw (b) to align specified throttle prima-
ry pickup mark on timing decal with timing point-
er. Retighten jam nut on adjustment screw.
NOTE: Primary pickup timing also determines en-
gine RPM, refer to “Idle Speed Adjustment” following.
b
a
NOTE: All timing adjustments made to outboard
under cranking speed conditions should be verified
with outboard running and adjustments made if
necessary. This is due to advance characteristics of
individual ignition systems.
2.
Remove timing light from No. 1 spark plug lead.
3.
Remove spark gap tools (91-63998A1) from
each spark plug boot.
4.
Install all spark plugs into cylinder heads. Torque
spark plugs to 20 Ib. ft. (27.0 N·m) and attach
spark plug leads to spark plugs.
5.
Reconnect WHITE/BLACK lead (a) (starboard
side of engine) from idle stabilizer at bullet
connector (b).
b
a
IDLE SPEED ADJUSTMENT
1.
With engine in water, connect fuel line to engine.
Start engine and allow to warm up.
2.
Place outboard in gear and monitor engine RPM.
If RPM is above or below recommended RPM
(see specifications), readjust primary pickup (a)
screw to attain recommended engine speed.
Retighten jam nut.
a
CAUTION
Engine idle RPM must NEVER EXCEED 750 RPM
in gear.
3.
With end of throttle cable connected to throttle
lever, hold throttle lever against idle stop. Adjust
throttle cable barrel to slip into barrel retainer on
cable anchor bracket with a very light preload of
throttle lever against idle stop. Lock barrel in
place.
4.
Check preload on throttle cable by placing a thin
piece of paper between idle stop screw and idle
stop. Preload is correct when paper can be
removed without tearing but has some drag on it.
Readjust cable barrel, if necessary.
IMPORTANT: Excessive preload on throttle cable
will cause difficulty when shifting from forward
to neutral. (Readjust throttle cable barrel, if
necessary.)
NOTE: Carburetors are equipped with idle mixture
adjustment screws. See carburetor specifications for
mixture screw adjustment.
NOTE: If sufficient throttle cable barrel adjustment is
not available, check for correct installation of link rod
between the throttle lever and throttle cam. Each end
of this link rod must be threaded into its plastic barrel
until it bottoms against the throttle lever or throttle
cam casting, then turned out only far enough to
obtain correct orientation of link rod (less than one
turn). All timing adjustments must be reset after this
procedure.