1985 Ski-Doo snowmobile Service Manual, Page 53Get this manual
Section 02 ENGINE SUb-section 02 (253 ENGINE TYPE)
To synchronize pump with carburetor:
Eliminate the throttle cable free-play by pressing the throttle lever until light resistance is felt, then hold in placeThe aligning marks on the pump casting and on the lever must alignIf not, loosen the adjuster nut and adjust accordinglyRetighten the adjuster nut
WARNING: Ensure not to operate carburetor throttle mechanismSecure the rear of the vehicle on stand
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