Chrysler 100, 115 and 140 HP Outboard Motors Service Manual, OB 3439, Page 45Get this manual
adjustment orifice into the by-pass chamber mixing with additional air supplied through the secondary idle ports discharging into the throttle bore through the primary idle discharge portFigure 2 which also lifts fuel from the nozzle well into the air streamThe open position of the throttle determines the quantity of intermediate fuel being delivered from the main nozzle which mixes downstream with the existing intermediate and idle fuel already flowing in the systemFigure 3
High Speed OperationAs the throttle opening is increased to obtain high speed operation, suction at the main nozzle also increases, lifting greater quantities of fuel from the nozzle wellAs this occurs, the fuel level within the nozzle well tends to lowerAs the fuel continues to lower in the fuel well, you will note that the bottom end of the idle tube will eventually become exposed to incoming carburetor air through the main nozzle air bleed located in the choke bore When this level is reached, the idle tube is no longer in solid fuel, and the intermediate fuel being delivered through the idle system lessensAt this time the throttle would be wide open or near wide open position during maximum or near maximum fuel delivery to the engine High speed fuel then flows from the fuel bowl through the main fuel jet, through the nozzle well area, through the main nozzle and into the engineThe fuel level in the nozzle well is dependent on the fuel being consumed by the engine, and this in turn dependent upon the throttle opening Figure 4