Ski-Doo FORMULA S 1997, Shop Manual

Page: 368 / 926

Section 03 ENGINE
Sub-Section 03 (454, 494, 583 AND 670 ENGINE TYPES)
03-03-5
NOTE: The following procedures can be
done without removing the engine from
chassis.
CLEANING
Discard all gaskets and O-rings.
Clean all metal components in a non-ferrous met-
al cleaner.
Scrape off carbon formation from cylinder ex-
haust port, cylinder head and piston dome using a
wooden spatula.
NOTE: The letters “AUS” (over an arrow on
the piston dome) must be visible after clean-
ing.
Clean the piston ring groove with a groove cleaner
tool, or with a piece of broken ring.
DISASSEMBLY
Place a clean cloth over crankcase then with a
pointed tool inserted in piston notch, remove cir-
clip
no. 20 from piston no. 21 .
To remove piston pin no. 19 , use piston pin puller
(P/N 529 0290 00) as follows:
– Fully screw puller handle.
– Insert puller end into piston pin.
– Install adaptor (P/N 529 0236 00) then screw
extracting nut (LH threads).
– Hold puller firmly and rotate puller handle coun-
terclockwise to pull piston pin.
NOTE: 0.25 mm oversize piston and rings
are available if necessary except for 454 en-
gine.
RAVE System
NOTE: RAVE stands for Rotax Adjustable
Variable Exhaust.
Remove spring clip no. 3 , cover no. 5 and spring
no. 6 .
Cut clamp no. 8 (remove spring on 454) and un-
screw valve piston no. 7 .
Spread clamp no. 10 (except 454) and remove
bellows no. 9 .
Remove cylindrical screws no. 11 and their wash-
ers no. 12 then valve rod housing no. 13 .
Pull out exhaust valve no. 16 .
1. Exhaust valve
INSPECTION
Refer to ENGINE DIMENSIONS MEASUREMENT 03-
04.
RAVE System
Check valve rod housing and cylinder for clogged
passages.
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A01B1AA
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A03C1PA
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