1997+ Mercury 35/40HP 2 Cylinder Outboards Service Manual PN 90-826148R2, Page 152Get this manual
Carburetor Adjustments Initial Starting Adjustment
Turn idle mixture screw adjustment "in" (clockwise) until it seats lightly then, back off 1-12 turns
Carburetor Float Adjustment
1Remove carburetor as outlined in "Carburetor
Removal," following2Remove fuel bowl and gasket and check float lev-
el using carburetor scale
916 in(14.29 mm)
Idle Speed Adjustment
1Adjust engine idle RPM as outlined in Section 2C
"TimingSynchronizingAdjusting
Idle Mixture Screw Adjustment
1Start engine and allow to warm-upThrottle back
With Gasket Removed
engine to idle for about one minute2With engine running at idle speed in "Forward"