Polaris 2001 High-Performance Snowmobile Service Manual (PN 9916690), Page 149Get this manual
CARBURETION Keihin Carburetor Service Leak Testing Needle and Seat
1After adjusting float level, place carburetor in an inverted position2Connect pressure tester to fuel inlet fittingApply psi pressure and observe for one minuteThe needle and seat should hold pressure indefinitelyIf the pressure drops, carefully inspect the needle and the needle seatThe needle can be replaced if necessaryThe needle seat cannot be replacedIf the seat surface is damaged replace the carburetorPressure Tester PN 2870975