2000 Polaris Virage TX, SLX, Pro 1200, Genesis, Genesis FFI Personal Watercraft Service Manual, Page 78Get this manual

2000 Polaris Virage TX, SLX, Pro 1200, Genesis, Genesis FFI Personal Watercraft Service Manual, Page 78

http:ReadManm FUEL SYSTEMCARBURETION System OperationKeihin The Keihin carburetor uses floatless diaphragm typeSeveral separate
pressure on the control arm in the fuel chamberThis reduces pressure on the inlet needle and allows it to lift more easily
off the seatWhen the engine is running, pressure in the carburetor venturi (and therefore the fuel chamber) is less than
atmosphericThis increases the effect of the atmospheric pressure on the diaphragm and lever and overcomes spring pressureWhen
the lever return spring pressure is overcome by these forces, the needle lifts off of the seat or "pops off', allowing pressurized
fuel from the fuel pump to enter the fuel chamberFuel inlet needle "pop off' pressure is influenced by many factorsAtmospheric
pressure, venturi low pressure, the amount of spring pressure on the control arm, and fuel pressure from the fuel pump all
have an affect on operating pop off pressureAll of these forces combined regulate the amount of fuel that enters the carburetor