1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 112Get this manual
IMPORTANT: Use of enrichener if engine is warm could result in engine floodingENRICHENER VALVE TEST Push key (or choke button) inValve should click
No Click Check for battery voltage to yellowblack wire at terminal block on engine when key (or choke button) is pushed in
Click Squeeze primer bulb until bulb is firmRemove lower hose from fitting on enrichener valvePlace container under valve, then push key (or choke button)Check for fuel flow from fitting
Battery Voltage Indicated Check for loose or corroded connection between YELLOWBLACK wire and black wire (under same screw at terminal block)Check that other BLACK wire at terminal block is properly groundedRepair connection(s) as necessary, then push key (or choke button) inIf enrichener valve DOES NOT click, replace valve