2005 Ski-Doo Racing Handbook, Page 390Get this manual
SECTION 082005 MX 550 AND 380 FC
A09C0VA
TYPICAL 1Unused shim(s) here 2Adjust here 3Positioning noses 4Some engines only
Select pulley halves so that the one with positioning noses will be on fan sideEnsure to insert these noses into fan notchesOnce fan belt is properly adjusted, torque fan nut to 48 Nm (35 lbfft) using holder wrench (PN 420 876 357), as shown in the following photoNOTE: Apply Loctite 243 (blue) on fan nut threadsA03C2BA
TYPICAL 1Measure deflection here 2Fish scale