1999 Ski-Doo Factory Shop Manual Volume Two, Page 168Get this manual
Section 04 ENGINE Subsection 09 (ROTARY VALVE, COOLANT PUMP AND RESERVOIR)
ROTARY VALVE TIMING At disassembly, before removing rotary valve, note original rotary valve timing: it may be out of specifications by to degrees of retard or advanceTo do so, bring MAG piston to TDC and scribe mark on crankshaft end at top (12 o'clock) and also on upper crankcase halfMark position of rotary valve shaft gear in relation to upper crankcase
When the same crankcase is reassembled, the first timing method is to be followedHowever, since replacement crankcases do not have timing marks (ridge), the second method is requiredTake note that the second method is more accurate and may be used any time
Installation
To correctly install rotary valve, proceed as follows: Turning crankshaft, bring MAG side piston to Top Dead CenterUse dial indicator (PN 414 104 700)414 104 700
A00B2EA
A16C16A
1Mark here 2MAG piston at TDC
A degree wheel (PN 414 352 900) is required to measure rotary valve opening and closing angles in relation with MAG side pistonDegree wheel will be installed on rotary valve shaft for measurements32