User manual DAELIM BESDI 125 SERVICE MANUAL

[. . . ] HOW TO USE THIS MANUAL This manual describes effective maintenance procedure for the SC125 manufactured by DAELIM Motor Co. , Ltd. To ensure safety and optimal operating conditions of the vehicle, carry out regular inspections according to the maintenance schedule (Section 3). Sections 1 through 3 provide information on overall vehicle; section 4, assembly and disassembly procedures for external components, and section 5 describes maintenance procedure for the engine, frame and electrical systems. To facilitate use of this manual, each page starts with disassembly and system diagrams, service information, and troubleshooting guide. [. . . ] Be careful not to grind the seat more than necessary. Using a 45 degree cutter, remove any roughness or irregularities from the seat. Using a 37 degree cutter, remove valve seat material. of the existing 9-9 CYLINDER HEAD / VALVES Using a 55 degree cutter, remove the bottom old seat. of the Using a 45 degree cutter, cut the seat to the proper width. If the contact area is too high on the valve, the seat must be lowered using a 37 degree flat cutter. Refinish the seat to specifications, using a 45 degree finish cutter. If the contact area is too low on the valve, the seat must be raised using a 55 degree inner cutter. Refinish the seat to specifications, using a 45 degree finish cutter. 9-10 CYLINDER HEAD / VALVES After cutting the valve seat, apply lapping compound to the valve face, and insert the valve with a valve guide reamer. NOTE Do not excessively press and turn the valve to set it as it may cause damage. The seat surface may become worn on one side if the valve is set in the same position. Turn the valve slightly when setting it. Take precautions not to allow compound to get into the clearance between the stem and guide while the valve is being set. IN, EX VALVE Install new stem seals. NOTE Replace the stem seals with new ones whenever a stem seal is removed. Lubricate each valve stem with molybdenum disulfide grease and insert the valve into the valve guide. CAUTION Turning a valve too fast can damage the stem seals. Install the spring seats, valve springs and retainers. NOTE For valve spring with varying pitch, install the valve springs with the narrow pitch end facing down. Compress the valve springs with the valve spring compressor and install the valve cotters. CAUTION Compressing the valve spring more than necessary when installing the valve cotters may cause loss of valve spring tension. TOOL : VALVE SPRING COMPRESSOR 9-11 CYLINDER HEAD / VALVES Tap the valve stems gently with a soft hammer to firmly seat the cotters. CAUTION Take necessary precautions not to damage the valve. Install the spark plug. TORQUE : 1. 2 kgf m CYLINDER HEAD ASSEMBLY Clean any gasket material from the cylinder mating surface. Install the cam chain guide to the cylinder. Install the dowel pins and new gasket. Install the cylinder head. 9-12 CYLINDER HEAD / VALVES CAMSHAFT ASSEMBLY Apply engine oil to the rocker arm shaft, and assemble the rocker arm to the camshaft holder. Tighten the rocker arm shaft with 5mm bolts, and align the bolt hole of the camshaft holder with the fitting side of the rocker arm shaft. Check the camshaft assembly for abnormal condition, and place it on the cylinder head. Put the cam chain on the cam sprocket. Slowly rotate the crankshaft counterclockwise, and align the T mark of the flywheel with the index mark of the RH. crank case cover. CAUTION Take precautions not to allow the cam chain to come off the camshaft timing gear while turning the camshaft. 9-13 CYLINDER HEAD / VALVES Apply engine oil to the camshaft, and install it on the cylinder head with the cam thread facing downward. Assemble the cam chain and cam sprocket after matching the cam sprocket timing mark in parallel with the top of the cylinder head. Install the dowel pins on the cylinder head. Install the camshaft holder. CAUTION The hole of the camshaft holder and the fitting section of the rocker arm shaft fit section must be in alignment. Of IN and EX, the shorter rocker arm should be installed on the IN side. Apply engine oil to the threaded part; install the camshaft holder nut and bolts, and tighten them driving with 2 - 3 times. TORQUE VALUE : 2. 9 kgf m NUT CAM COVER PLATE Remove the pan screws and seals from the cam chain tensioner lifter. Rotate the tensioner shaft clockwise with a small driver, and insert the shaft into the body completely. CAUTION If the cam chain tensioner lifter is dropped, the shaft will advance by the spring force. 9-14 CYLINDER HEAD / VALVES Fix the tensioner shaft with a hard clip. Assemble a new gasket to the tensioner lifter, and install the tensioner lifter on the cylinder. Tighten the tensioner mounting bolts. TORQUE VALUE : 1. 2 kgf m Remove the tensioner shaft clip from the tensioner lifter. Assemble the O-ring and pan screws to the tensioner lifter. TORQUE VALUE : 0. 4 kgf m Fill clean engine oil into the operating parts of the cylinder head. Remove oil from the cylinder head cover grooves, and accurately assemble the gasket to the cover. Install the cylinder head cover. Tighten the cylinder head cover bolts. TORQUE VALUE : 0. 9 kgf m Shroud comp. [. . . ] Disconnected or shorted high tension cord. Disconnected or shorted ignition coil wire. Warped or cracked cylinder head or cylinder. Recheck the engine. Fuel is supplied Check the spark plug. Weak or no spark. Good spark Measure the cylinder compression. Compression normal Low or no cylinder compression. Start the engine in the following procedure. Engine won't start. Engine starts but stops immediately. Remove the spark plug, and recheck it. Dry spark plug Spark plug wet. Restart the engine in the following procedure. Engine starts Engine won't start. Completion 19-1 TROUBLESHOOTING ENGINE STALLS, HARD TO START, ROUGH IDLING CAUSE OF TROUBLE Open the drain screw, and check fuel flow to the carburetor. [. . . ]