Mercury 40 Service Manual page 125

Carburetor Adjustments
Idle Speed Adjustment
NOTE: The engine should be completely warmed up for the adjustment. Correct adjust-
ments can not be obtained in a cold condition.
1. With the outboard in neutral gear and in the water, start engine and allow to warm up.
2. Shift outboard into forward gear.
3. Turn the idle adjustment screw located on the #4 (bottom) carburetor to attain the speci-
fied idle rpm.
a
a -
4. Rev engine 2 or 3 times and allow to idle for 15 seconds.
90-828631R3 MARCH 1999
Idle rpm Adjustment Screw
Idle rpm in Forward Gear
45 hp
40/50 hp
If the engine holds a stable idle condition, then no other adjustments are necessary.
If the engine has an unstable idle condition, then carburetor synchronization is re-
quired. Refer to Carburetor Synchronization following.
TIMING, SYNCHRONIZING, & ADJUSTING
850 25 rpm
725 25 rpm
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