2004 Ski-Doo REV Series Factory Service Manual, Page 188Get this manual
Section 05 2TEC ENGINE MANAGEMENT Subsection 01 (OVERVIEW)
OPERATING PRINCIPLE
For this SDI 2-stroke engine, highly advanced engine management system (EMS) has been used to ensure high power output combined with cleanest combustionAn ECM (Engine Control Module) calculates the proper airfuel mixture and ignition timing for each cylinder separatelyThe fuel is injected into the transfer port of each cylinder
The fuel pump module is located inside the fuel tankThe module includes the fuel pump, the fuel pressure regulator and the fuel level sensor (if so equipped)
AIR INDUCTION
Through air filter mounted LH side panel, air goes into air silencerThe ECM measures at this point air pressure and temperatureThen, air for combustion is drawn through two throttle bodiesThe air flow is controlled by two throttle platesThe air continues through the reed valves into the cylinder base then the crankcaseA33I06A
The fuel pressure regulator controls the pressure in the system and allows the excess of fuel to return to the fuel tankThe fuel pressure regulator regulates the fuel pressure at 400 kPa (58 PSI)