1999 Ski-Doo Factory Shop Manual Volume Two, Page 192Get this manual
Section 04 ENGINE Subsection 11 (CARBURETOR AND FUEL PUMP)
For the pressure to vary within the bowls, the solenoid is activated in part by the DPM during each cycleThis is what is called the duty cycleIn other words, the solenoid will not open throughout the whole cycleThe duty cycle depends on the engine coolant temperatureThe colder the engine, the longer the duty cycleTherefore, the solenoid will stay open longer, thus giving way to pressureMPEM reads engine temperature at once (when starting) through sensor
MPEM reads air temperature through sensorA03I0WA
1Air temperature sensor
Manifold Air Jet
This jet allows the atmospheric pressure to reach carburetor bowls when the DPM SYSTEM is on standby (returned to atmospheric pressure)1