Polaris 2001 High-Performance Snowmobile Service Manual (PN 9916690), Page 155Get this manual
CARBURETION Mikuni TM-38TM-40 Carburetor Service
3Place carburetor in an inverted position4Connect 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 and seat can be replaced as an assembly (needle and seat comes with float)If the seat surface is damaged replace the carburetorPressure Tester PN 2870975