Mercury 75 Service Manual page 113

INITIAL STARTING ADJUSTMENTS
NOTE: For adjusting carburetor throttle linkage and
synchronizing carburetors, see section "Timing/
Synchronizing/Adjusting" of this manual.
After service or replacement of carburetor, turn low
speed mixture screw adjustment in (clockwise) until
it seats lightly, then back off (each carburetor) to
specifications (65JET/75/90 – 1 turn on #1 carb; 1 –
1-1/2 turns on #2 and #3 carbs). This will permit en-
gine start-up.
LOW SPEED MIXTURE ADJUSTMENTS
1. Start engine and allow to warm up (run for several
minutes). Throttle back to idle for about one min-
ute to allow RPM to stabilize.
2. With engine running at idle speed (in water) in
"Forward" gear (prop on), turn low speed mixture
screw, IN (clockwise) until engine starts to "bog"
down and misfire. Back out 1/4 turn or more.
3. Check for too lean mixture on acceleration.
4. DO NOT adjust leaner than necessary to attain
reasonable smooth idling. When in doubt, stay on
the slightly rich side of the adjustment.
IDLE ADJUSTMENT
1. With engine in water, connect electrical harness
and fuel line to engine. Start engine and allow to
warm up.
2. Shift into "Forward" gear and adjust carburetor
low speed mixture screws properly (refer to "Car-
buretor" section).
3. Holding throttle arm at idle position, adjust idle
timing screw to attain an engine idle RPM of
650-700 RPM in "Forward" gear. Turn off engine.
2C-4 - ELECTRICAL
2 - 8 BTDC
0 2 8
a - Throttle Arm
b - Idle Timing Screw
90-830234R3 DECEMBER 1997
b
a
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