5. FUEL SYSTEM ATV 50 SERVICE INFORMATION GENERAL INSTRUCTIONS · When working with gasoline, keep away from sparks and flames.. · Note the locations of O-rings when disassembling and replace them with new ones during assembly. · All cables, fuel lines and wires must be routed and secured at correct locations. · Bleed air from the oil lines whenever they are disconnected. SPECIFICATIONS ATV 50 Venturi dia. 14 mm (0.56 in) Identification number PB Float level 8.6 mm (0.34 in) Main jet # 80 Slow jet # 38S Air screw opening 2 1/2 Idle speed 1800100 rpm Throttle grip free play 14 mm (0.04 0.16 in) SPECIAL TOOL Float level gauge TROUBLESHOOTING Engine does not start Lean mixture · No fuel in tank · Clogged fuel jets · Faulty float valve · Too much fuel getting to cylinder · Clogged fuel cap vent · Float level too low · Clogged fuel filter · Clogged fuel filter · Clogged air cleaner · Clogged air cleaner · Bent, kinked or restricted fuel line Engine idles roughly, stalls or runs poorly Rich mixture · Incorrect idle speed · Clogged air cleaner · Faulty float valve · Ignition malfunction · Intake air leaks · Float level too high · Compression too low · Fuel contaminated · Clogged air jets · Incorrectly adjusted air screw · Faulty reed valve · Incorrect float level · Clogged fuel jets 5-2