Mercury 45 Jet 50-55 - Timing Adjustments; Idle Timing Adjustment

ELECTRICAL and IGNITION - 2C-390-817643R1 DECEMBER 1996
4. Hold throttle arm at idle position. Adjust cam follower
so that a clearance of .005 in.-.040 in.(0.13 mm-1.02
mm) exists between roller (e) of cam follower and
throttle cam (f). Tighten screw (a) securing cam follow-
er.
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.005 in.
.040 in.
a
e
f
(0.13 mm
1.02 mm)
5. Hold throttle arm (a) against full throttle stop screw (b).
Adjust full throttle stop screw to allow throttle shutters
to open fully while providing approximately .015 in. (.38
mm) freeplay in throttle linkage to prevent carburetor
throttle shutters from acting as throttle stops at wide
open throttle. Tighten locknut (c) on stop screw (b).
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6. Reinstall sound box cover.
Timing Adjustments
!
CAUTION
Engine may be timed while cranking engine with start-
er motor. To prevent engine from starting when being
cranked, all spark plugs must be removed.
1. Insert Spark Gap Tool (91-63998A1) into each spark
plug boot and attach alligator clips to good engine
ground.
2. Disconnect remote fuel line from engine.
3. Connect remote control electric harness to engine wir-
ing harness.
4. Remove throttle cable barrel from barrel retainer.
IDLE TIMING ADJUSTMENT
1. Connect timing light to No. 1 (TOP) spark plug lead.
! WARNING
While cranking engine, keep clear of propeller as it
may rotate.
2. Shift engine to neutral.
IMPORTANT: To time engine at cranking speed, a fully
charged battery must be used.
3. Hold throttle arm at idle position, crank engine with
starter motor and adjust idle timing screw (a) to align
2 degrees ATDC
timing mark of flywheel with timing
pointer. Tighten locknut (b).
NOTE: Timing will be 2° - 6° ATDC after adjusting idle RPM.
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a
b
010
2° ATDC
10