1990 Johnson Evinrude "ES" 60 thru 70 Service Manual, P/N 507873, Page 64Get this manual
Description of Fuel System
1The unit is combination mechanical fuel and oil pump, powered by crankcase pressure and vacuum pulses, which responds to various engine power settings by injecting the proper amount of oil into the fuel system pumps incorporate circuit "no oil" situation
that warns the operator of a
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 circuits