2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 106Get this manual
FUEL SYSTEM 3Measure the height from the float bowl mating surface to the top of step of the float as shown in the previous photoBoth sides of float should be parallel to each otherThe measurement should be made at the midpoint on top of the float using Float Adjustment Tool (PN 2872314) or vernier caliperWhen measuring the height, be sure the inlet needle valve spring is not compressed
Fuel Level test
A fuel level test can be performed on some models if the drain hose fitting is accessibleBe sure to reattach the bowl drain hose after performing the testA fuel level test allows you to observe the height of the fuel in the float bowl without removing the carburetorThe fuel level can be observed with the engine either running or shut off, however, engine must run briefly to allow fuel level to stabilize1Attach clear line to drain fittingBe sure line fits tightly on fittingPosition hose along side of carburetor as shown