User manual SYM CITYCOM 300I SERVICE MANUAL

[. . . ] FOREWORD HOW TO USE THIS MANUAL CONTENTS SERIAL NUMBER Citycom. 300i SERVICE MANUAL Homepage Contents Foreword This service manual contains the technical data of each component inspection and repairment for the SANYANG LH30W series scooter. The manual is shown with illustrations and focused on "Service Procedures", "Operation Key Points", and "Inspection Adjustment", providing technicians with service guidelines. If the style or the mechanical structures of the scooter, LH30W series scooter, are different from those of the photos or pictures shown in this manual, the actual vehicle shall prevail. Specifications are subject to changes without notice. Service Department SANYANG INDUSTRY CO. , LTD. Homepage Contents How To Use This Manual This service manual describes the basic information of different system parts and system inspection & service for SANYANG LH30W series scooter. [. . . ] Cylinder Head / Valve Cylinder Head Inspection Check if spark plug and valve holes are cracked. Service limit: 0. 05 mm Camshaft Inspect cam lobe height for damaged. Service Limit: IN: Replacement when less than 34. 860mm EX: Replacement when less than 34. 725mm Inspect the camshaft bearing for looseness or wear out. If any damage, replace whole set of camshaft and bearing. Rocker Arm Measure the cam rocker arm I. D. , and wear or damage, oil hole clogged?Service Limit: Replace when it is less than 12. 080 mm. Rocker Arm Shaft Measure the active O. D. Calculate the clearance between the rocker arm shaft and the rocker arm. Service Limit: Replace when it is less than 0. 10 mm. 6-8 To this chapter contents 6. Cylinder Head / Valve Valve spring free length Measure the free length of intake and exhaust valve springs. Service limit: Inner spring 35. 20 mm Outer spring 36. 90 mm Valve stem Check if valve stems are bend, crack or burn. Check the operation condition of valve stem in valve guide, and measure & record the valve stem outer diameter. Service Limit: IN: 4. 90 mm EX: 4. 90 mm Valve guide Caution Before measuring the valve guide, clean carbon deposits with reamer. Tool: 5. 0 mm valve guide reamer Measure and record each valve guide inner diameters. Service limit: 5. 03 mm The difference that the inner diameter of valve guide deducts the outer diameter of valve stem is the clearance between the valve stem and valve guide. Service Limit: IN0. 08 mm EX0. 10 mm 5. 0 mm valve guide reamer Caution If clearance between valve stem and valve guide exceeded service limit, check whether the new clearance that only replaces new valve guide is within service limit or not. If clearance still exceeds service limit after replaced valve guide, replace valve stem too. Caution It has to correct valve seat when replacing valve guide. 6-9 To this chapter contents 6. Cylinder Head / Valve Valve Stem Replacement Heat up cylinder head to 100~150 with heated plate or toaster. Valve guide driver 5. 0mm Caution Do not let torch heat cylinder head directly. Hold the cylinder head, and then press out old valve guide from combustion chamber side. Tool: Valve guide driver: 5. 0 mm Caution Check if new valve guide is deformation after pressed it in. When pressing in the new valve guide, cylinder head still have to be kept in 100~150. Tool: Valve guide driver: 5. 0 mm Wait for the cylinder head cooling down to room temperature, and then correct the new valve guide with reamer. Valve guide driver 5. 0 mm Caution Using cutting oil when correcting valve guide with a reamer. Correct valve seat, and clean up all metal residues from cylinder head. Tool: Valve guide reamer: 5. 0 mm Valve guide reamer 5. 0 mm 6-10 To this chapter contents 6. Cylinder Head / Valve Valve Seat Inspection and Service Clean up all carbon deposits onto intake and exhaust valves. [. . . ] When the engine is running, the negative pressure of intake manifold opens the purge control valve, forces HC off from activated carbon and then sucks it into engine together with air from bottom of the canister. The canister can be used repeatedly without reducing its performance because of the system's purge function. Trouble Diagnosis: No fuel in the fuel tank Loosen vacuum hose of the fuel pump Jammed hose in the system 4. Cautions: Do not exceed the reed valve of the fuel filler when filling fuel. [. . . ]