4. LUBRICATION SYSTEM VITALITY 50 SERVICE INFORMATION (4-STROKE) GENERAL INSTRUCTIONS · The maintenance of lubrication system can be performed with the engine installed in the frame. · Use care when removing and installing the oil pump not to allow dust and foreign matters to enter the engine and oil line. · Do not attempt to disassemble the oil pump. The oil pump must be replaced as a set when it reaches its service limit. · After the oil pump is installed, check each part for oil leaks. SPECIFICATIONS Item Standard (mm) Service Limit (mm) Inner rotor-to-outer rotor clearance 0.15 0.20 Oil pump Outer rotor-to-pump body clearance 0.150.20 0.25 Rotor end-to-pump body clearance 0.040.09 0.12 TROUBLESHOOTING Oil level too low Poor lubrication pressure · Natural oil consumption · Oil level too low · Oil leaks · Clogged oil filter or oil passages · Worn or poorly installed piston rings · Not use the specified oil · Worn valve guide or seal 4-4