1999 "EE" 90, 115 FFI, 150, 175 V4, V6 FFI Outboards Service Manual, P/N 787024, Page 51Get this manual
Fuel Lines
Two fuel lines attach to each injector; one supplies fuel, while the other returns fuelThey're held to the injectors by individual wire clipsThe lines connect to two junction blocks One block divides circulation pump fuel supply between the port and starboard cylinder banks, while the other block combines return fuel for routing to the vapor separator
Cylinder Heads
Each head mounts one fuel injector and one spark plug per cylinderEach head also features temperaturepressure thermostatIt's located at the top of the head in the water passage coming from the cylinder blockIt can be opened either by water temperature or by water pressureThe heads also mount the water temperature switch and water temperature sensorThe switch is in the starboard head, while the sensor is in the port headPistons
The top of each piston has unique configurationEach is slightly domed, and features small cylindrical "splash port"Injector fuel spray is directed into the splash port which in turn reflects it upward throughout the combustion chamberThis provides finely atomized fuelair mixture for easier ignition and cleaner burning