Ski-Doo Formula 500 1998, Shop Manual

Page: 146 / 398

Section 04 ENGINE
Subsection 09 (ROTARY VALVE, COOLANT PUMP AND RESERVOIR)
04-09-6
4,6, Rotary Valve Shaft and Loctite 648
To install rotary valve shaft proceed as follows
with the suitable tools:
– rotary valve seal pusher (P/N 420 8766 07)
– seal protector sleeve (P/N 420 8769 80)
1. Rotary valve shaft
Apply Loctite 648 (P/N 420 8997 88) on shaft
threads.
18,19, Pump Housing Bolt and Loctite 242
(Blue)
Apply Loctite 242 (blue) on bolt threads.
Rotary Valve
The rotary valve controls the opening and closing
of the inlet ports. Therefore its efficiency will de-
pend on the precision of its installation.
IDENTIFICATION OF THE ROTARY VALVE
There is no identification code on the valve. To
find out the duration, place an angle finder on the
valve and measure the valve cut-out angle.
ROTARY VALVE TIMING
At disassembly, before removing rotary valve,
note original rotary valve timing: it may be out of
specifications by 1 to 4 degrees of retard or ad-
vance. To do so, bring MAG piston to TDC and
scribe a mark on crankshaft end at top (12 o’clock)
and also on upper crankcase half.
Mark position of rotary valve shaft gear in relation
to upper crankcase.
-
CAUTION
Crankcase halves must be separated and
crankshaft must not be present to install ro-
tary valve shaft ass’y in crankcase.
A16C19A
420 8765 00
A16C1AA
420 8769 80 1
420 8766 07
Engine Type
Rotary Valve
P/N
420 924 XXX
Valve Duration
(Cut-out Angle)
°
494 MX Z 502 159
494 All models
except MX Z
509 147
583 MX Z, GT
and Formula
583/Z
502 159
583 Summit 509 147
670 500 164