User manual SYM AW12W-A

[. . . ] In addition, please refer to the manual contents in detail for the model you serviced in inspection and adjustment. The first chapter covers the general information and the trouble diagnosis. The second chapter covers the periodic maintenance information and the special tool models. The third to the 11th chapters cover the engine and the driving systems. [. . . ] Remove spark plug. 4 bolts Remove cylinder head cover (4 bolts). 4 bolts 6-4 To this chapter contents 6. Cylinder Head / Valve Remove the side cover mounting blots of cylinder head, and then take out the side cover. 3 bolts Remove left crankcase cover, and turn the Turn the drive face, and align the timing mark on the sprocket with that of cylinder head, piston is at TDC position. Remove cam sprocket bolts and then remove the sprocket by prying chain out. Timing mark 2 bolts Bolt ×2 Remove the 2 cylinder head mounting bolts from cylinder head right side, and then remove 4 nuts and washers from cylinder head upper side. Remove the cylinder head. 4 nuts Remove cylinder head gasket and 2 dowel pins. Clean up residues from the matching surfaces of cylinder and cylinder head. 2 dowel pins Caution Do not damage the matching surfaces of cylinder and cylinder head. Avoid residues of gasket or foreign materials falling into crankcase as cleaning. Cam chain guide 6-5 To this chapter contents 6. Cylinder Head / Valve Cylinder Head Disassembly Remove cam shaft setting plate (1 bolt). 1 bolt Cam shaft setting plate Remove rocker arm shafts and rocker arms. Special Service Tool: Rocker arm and cam shaft puller SYM-1445100 Rocker arm shaft and cam shaft puller Remove cam shafts. Special Service Tool: Rocker arm and cam shaft puller SYM-1445100 Cam shafts Rocker arm shaft and cam shaft puller Use a valve cotter remove & assembly tool to press the valve spring, and then remove valves. Caution In order to avoid loosing spring elasticity, do not press the spring too much. Thus, press length is based on the valve cotter in which can be removed. Special Service Tool: Valve cotter remove & assembly tool SYM-1471110-SY125 Valve cotter remove and assembly tool 6-6 To this chapter contents 6. 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. Grind valve seat with a rubber hose or other manual grinding tool. Caution Do not let emery enter into between valve stem and valve guide. Clean up the emery after corrected, and apply with engine oil onto contact faces of valve and valve seat. Remove the valve and check its contact face. Caution Replace the valve with new one if valve seal is roughness, wear out, or incomplete contacted with valve seat. Valve seat width Valve seat inspection If the valve seat is too width, narrow or rough, corrects it. Valve seat width Service limit: 1. 6mm Check the contact condition of valve seat. Valve seat grinding The worn valve seat has to be ground with valve seat chamfer cutter. Use 45° valve seat chamfer cutter to cut any rough or uneven surface from valve seat. Roughness Caution After valve guide had been replaced, it has to be ground with 45° valve seal chamfer cutter to correct its seat face. Use 32° cutter to cut a quarter upper parts out. 45° Old valve seat width 32° 6-11 To this chapter contents 6. Cylinder Head / Valve Use 60° cutter to cut a quarter lower parts out. Remove the cutter and check new valve seat. Old valve seat width 60° Use 45° cutter to grind the valve seat to specified width. Caution Make sure that all roughness and uneven faces had been ground. Grind valve seat again if necessary. 1. 0mm 45° Coat the valve seat surface with red paint. Install the valve through valve guide until the valve contacting with valve seat, slightly press down the valve but do not rotate it so that a seal track will be created on contact surface. Contact surface too high Old valve seat width Caution The contact surfaces of valve and valve seat are very important to the valve sealing capacity. 32° If the contact surface is too high, grind the valve seat with 32° cutter. [. . . ] system gas introducing Vapor separator device To introduce blow-by gas into combustion chamber via a vapor separator for burning. 18-1 To this chapter contents 18. Emission Control System Evaporative Emission Control System (E. E. C. ) 1. To absorb fuel vapor and saving fuel consumption Fuel tank cap (closed type) Fuel vapor separator Fuel tank Vacuum hose Fuel hose Automatic control fuel cup Vapor purge control solenoid Vapor hose Carburetor Blow-by hose Air cleaner Activated- carbon canister Flesh air Fuel Fuel vapor Vacuum Flesh air inlet Engine 2. Principle of operation Vapor generated in fuel tank and fuel system through evaporation is collected in the confined system to prevent it from escaping into the atmosphere, at the same time, the vapor will be introduced into a charcoal canister where the hydrocarbon in the vapor will be absorbed by activated carbon. [. . . ]