Mercury Mariner V-250 V-275 Outboard Service Shop Manual 1990, Page 90Get this manual
Enrichener System Description
The enrichener system provides the engine with rich
fuel charge for sta rting ease of cold engineThe
system consists of an electrically operated enrichener valve which is connected by hoses to the carburetorsFuel is gravity fed to th valve fro the float bowl of the
top carburetor via hoseWhen the key (or choke button) is pushed in (and held in) current is sent to the valve causing it to open, which allows fuel to pass thruThe fuel passes thru hose and is supplied to the eng ine via fittings located in the intake manifold of the middle and bottom carburetorsWhen the key (or choke button) is releasedthe valve wi ll return 10 the closed position The valve can be operated manually if valve fails to operate electricall y
Enrichener Valve Test
Push key (or hoke button) In Valve should clickN Click Check tor battery voltage to yellowlblack wire at terminal block on engine when key (or choke bullon) Is pushed inClick Squeeze primer bulb until bulb is firm Remove hose from filling on bollom of enrichener valvePlace container under valve, then push key (or choke bullon)Check for luel flow from fillingNo VoUage Indluted Check toropen in yellow black wire between key switch (or choke bUllon) and terminal block