Bombardier SeaDoo 1990 factory shop manual, Page 61Get this manual
Section 03 ENGINE Sub-section 06 (ROTARY VALVERESERVOIR)
Rotary Valve CoverValve Gap
A gap must be maintained between rotary valve and crankcase To measure this gap, use feeler gage inserted between rotary valve and upper half crankcase with rotary valve cover in place WITHOUT its O-riung
Check as much surface as possibleFollow the same procedure for lower half crankcase
Rotary Vallve Shaft Defllection
Deflection is measured with dial gauge Install rotary valve shaft in crankcase half, without its gear