5B-10 - MERCARB 2 BARREL CARBURETOR 90-823225--1 1096
2. Turn idle mixture needle in until lightly seated,
then back needle out 1-1/4 turns.
72281
a
a - Idle Mixture Needle
Final Idle Speed and Mixture
IMPORTANT: Boat must be in the water and en-
gine at normal operating temperature to accu-
rately check and adjust idle speed and mixture.
Carburetor should be set so that engine idles
smoothly within range given under “Specifications,”
with boat in the water, engine at normal operating
temperature and drive unit in forward gear. To adjust
idle speed and mixture, proceed as follows:
IMPORTANT: DO NOT attempt to compensate for
other engine problems (incorrect ignition timing,
faulty ignition components, low compression,
vacuum leaks, etc.) with carburetor adjustments.
This will only cover the problem, which must be
corrected if engine is to achieve maximum fuel
economy and performance.
1. Connect an accurate shop tachometer to engine.
IMPORTANT: DO NOT turn idle mixture needle
tightly into seat, as damage to needle and/or seat
may result.
72281
a
a - Idle Mixture Needle
2. If new or rebuilt carburetor has been installed,
turn idle mixture needle in (clockwise) until it
lightly contacts seat, then back out needle 1-1/4
turns. This will provide a sufficient setting to allow
starting engine.
3. Start engine and run at 1500 RPM until engine
reaches normal operating temperature.
!
WARNING
DO NOT leave the helm unattended while per-
forming idle speed and mixture adjustments, fol-
lowing. BE CAREFUL NOT TO ACCIDENTALLY
ACCELERATE ENGINE WHILE PERFORMING
ADJUSTMENTS.
4. With boat in open water, place remote control in
forward gear, idle position.
5. Disconnect throttle cable barrel from anchor
stud. Be sure not to lose spacer on anchor stud.
6. Adjust idle speed adjustment screw to obtain
550-600 RPM, in neutral gear.
7. With engine running at specified RPM, adjust idle
mixture needle as follows:
a. Turn idle mixture needle in (clockwise) until
the engine speed begins to drop due to lean
mixture.
b. Turn idle mixture screw out (counterclock-
wise) until the speed begins to drop due to
rich mixture.
c. Turn screw in to a point between these two
extremes to obtain maximum engine smooth-
ness and RPM.
d. Readjust idle speed adjustment screw until
engine idles at 650-700 RPM in forward gear.
IMPORTANT: Refer to Section 2 - “Removal and
Installation” for throttle cable installation and ad-
justment.
To Next Page
Loading...
