1990 Johnson Evinrude 120 thru 140, 185 thru 225, 300 HP, P/N 507875, Page 79Get this manual
6718 6719 6776
Description of Fuel System
f21 1The pump is combination mechanical fuel and oil pump, powered by crankcase pressure and vacuum pulses, which respond to various engine power settings by injecting the proper amount of oil into the fuel systemThe pump incorporates circuit that warns the operator of "no oil" situation6720
f31 2The carburetors meter and distribute the fuel consumedThey control engine speed and power output by varying the intake charge densityTo react correctly to wide range of operating conditions, the carburetors have several discrete fuel mixing circuitsCarburetor calibration is controlled by an idle air bleed orificean intermediate air bleed orificeand high speed fuel orifice f41 3V8 engines are equipped with fuel manifold bypass valveL!] Although normally closed, the pressure sensitive bypass