Ski-Doo Formula S 1998, Shop Manual

Page: 90 / 338

Section 04 ENGINE
Subsection 03 (377, 443 AND 503 ENGINE TYPES)
04-03-5
NOTE: The following procedures can be done
without removing the engine from chassis.
CLEANING
Discard all gaskets. Use Gasket Remover (P/N
413 7085 00) to clean mating surfaces.
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” and arrow on the pis-
ton dome must be visible after cleaning.
Clean the piston ring grooves with a groove clean-
er tool, or with a piece of broken ring.
DISASSEMBLY
Remove top fan cowl, intake sockets and lower
fan cowl.
Remove cylinder heads.
All Engines Except 503
Place a clean cloth over crankcase to prevent cir-
clips
no. 10 from falling into crankcase. Then with
a pointed tool inserted in piston notch, remove cir-
clip from piston
no. 8 .
To remove piston pin no. 9 , use piston pin puller
(P/N 529 0290 00) as follows:
– Fully screw puller handle.
– Insert puller end into piston pin.
– Screw (LH threads) extracting nut.
– Hold puller firmly and rotate puller handle coun-
terclockwise to pull piston pin.
NOTE: The PTO cylinder or fan housing have to
be removed to give access to MAG piston pin
with the puller.
503 Engine
On these 503 engines, piston pin needle bearing
is mounted without a cage.
Use piston pin puller (P/N 529 0290 00) along with
expansion sleeve and locating sleeve.
– Place a clean cloth or rubber pad (P/N 529 0234
00) over crankcase to prevent circlips from fall-
ing into crankcase. Then with a pointed tool in-
serted in piston notch, remove piston circlip on
side where piston pin puller will be inserted.
– Insert piston pin puller (P/N 529 0290 00) then
install expansion sleeve over puller rod.
1. Expansion sleeve
– Pull out piston pin by unscrewing puller until
first thread of puller rod aligns with 503 mark.
1. 503 mark on puller
A01B1AA
A21C06B
1
529 0290 00
A21C05A
1