Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 155Get this manual
to open the regulator will equally increaseExample: If there is 50 p.s.L of air pressure on the air rail side of the diaphragm, 60 p.s.L of fuel pressure will be required to open the regulatorThe return fuel line (24) to the vapor separator is water cooledThis design is used to prevent cold fuel from the fuel tank hitting the hot fuel returning from the fuel rail and flashing off the light ends (boiling over)To equalize the pulses developed by the pumps (both air and fuel) tracker diaphragm (3) is installed in the starboard railThe tracker diaphragm is positioned between the fuel and air passagesThe tracker diaphragm is rubber diaphragm which expands and retracts depending upon which side of the diaphragm senses the pressure increase (pulse) occur if the battery is dead)The system will run off of the alternator