2006 Ski Doo REV Service Shop Manual, Page 213Get this manual
Section 04 FUEL SYSTEM Subsection 03 (DPM SYSTEM)
If water level drops to an even level in less than 10 seconds, the DPM manifold is defectiveReplace DPM manifold parts, (refer to Parts Catalog) and re-testIf test fails again, replace DPM manifoldIf you are unable to attain any amount of vacuum (water level increases and decreases immediately in tube), check your set-up and re-do the testIf you still cannot attain any vacuum, DPM manifold is defectiveReplace DPM manifold