2004 Skidoo ZX Series Service Manual, Page 141Get this manual
Section 04 ENGINES (2-STROKE) Subsection 02 (593, 593 HO SDI, 693 AND 793 SDI ENGINE TYPES)
With blade stopper no16 removed, check reed valve for proper tightnessThere must not be any play between blade and valve body when exerting finger pressure on blade at blade stopper locationIn case of play, turn blade upside down and recheckIf there is still play, replace blade andor valve body