2003 Polaris ATV Trail Boss 330 Factory Service Manual, Page 73Get this manual
PRESSURE RELIEF VALVE
The pressure relief valve opens to relieve any excess pressure from the oil pump if oil pressure reaches approximately 71 psiIt must be clean and have adequate spring pressure in order to seal properly1Remove cap bolt, sealing washer, spring, and relief valve from MAG side crankcase
Outer Feed Rotor to Crankcase Clearance: Std: .001-.003 (.0254-.0762 mm) Wear Limit: .004 (.1016 mm) 4Measure clearance between outer feed rotor and crankcase pocket with feeler gauge2Inspect free length of spring and check coils for distortion