Chrysler 25 and 30 HP Outboard Motors Service Manual OB 1894, Page 14Get this manual
SECTION IV (Cont HSet idle adjustment screw at point midway between positions noted in steps and G1Suddenly open throttle fully and note engine behaviorIf engine dies with "pop," it is too lean (correct by turning idle adjustment screw counterclockwise)If engine stumbles before accelerating, it is too rich (correct by turning idle adjustment screw clockwise)If engine hesitates but cause cannot be determined, turn idle adjustment screw 18" in either direction and note whether or not performance improvesIf performance does not change, continue turning screw 18 turn in same direction until there is difference in performanceJOn hand start models, idle stop screw is on starboard side of steering handleAdjust screw until engine idles at 600 :I: 50 R.P.Min "FORWARD" gearSee figure 5