1989 Ski-Doo Repair Manual, Page 70Get this manual
Section 02 ENGINE Sub-section 02 (253 ENGINE TYPE)
ADJUSTMENT
Prior to adjusting the pump, make sure all carburetor adjustments are completed
To bleed oil lines:
All oil lines should be full of oifIf requiredbleed the main oil line (between tank and pump) by loosening the bleeder screw until all air has escaped from the lineMake sure the tank is sufficiently filledCheck the small oil lines (bet'Neen pump and intake manifold)If required, fill the lines by running the engine at idle speed while holding the pump lever in fully open position(TYPICAL)
To synchronize pump with carburetor: