1985 Ski-Doo snowmobile Service Manual, Page 146Get this manual
Section 02 ENGINE Sub-section 07 (503 ENGINE TYPE)
,Crankcase lower half
2Crankcase upper half 3Lock washer mm (141
4567B910Screw MB 70 (6) Screw MB 45 IB) Loctite 515 Stud MB 173 IB) Cable grommet Rubber plug (5) Crankshaft
111213141516 17lB19
Ball bearing 6206(2) Shim mm (2) Spacer Seal Pr 0side Ball bearing 6207 O-ring Seal mag side Woodruff keV Loctite 242
CLEANING
Discard all seals, gaskets and O-rings Clean all metal components in non-ferrous metal cleanerRemove old sealant from crankcase mating surfaces with Bombardier sealant stripperCAUTION: Never use sharp object to scrape away old sealant as score marks incurred are detrimental to crankcase sealing
INSPECTION
The inspection of the engine bottom end must include the following measurements:
TOLERANCES MEASUREMENTS FITTING NEW PARTS (MIN (MAX NA NA WEAR LIMIT
Crankshaft deflection Connecting rod big end axial play
.08 mm 1.0031"1 1.0 mm 1.0394"1
DISASSEMBLY
General
To remove drive pulley, refer to "Drive pulley", section 03-03To remove magneto, refer to "Magneto" in this section