User manual YAMAHA YN50-2002 SERVICE MANUAL

[. . . ] YN505 2002 RN-AE1 SERVICE MANUAL YN50 SERVICE MANUAL © 2002 Yamaha Motor España, S. A. The reprinting or use of this material without the written authorisation of Yamaha Motor España, S. A is forbidden. Printed in Spain. WARNING This Manual was written by Yamaha Motor España, S. A. As it is not possible to give full mechanical instructions in a manual, it is presumed that the persons using the book to carry out the maintenance and repair of Yamaha/MBK motorcycles have a basic knowledge of the concepts and procedures inherent in the technology of motorcycle repair. [. . . ] Install: · Counterbalance · Race · Runner · Hub 3. Install: · Trapezoidal belt NOTE: The trapezoidal belt should be installed with the arrow facing towards the front. 4-32 ASSEMBLY AND ADJUSTMENT OF ENGINE MOT 6. Install: · Shim · Primary fixed pulley wheel · Washer · One-way clutch · Conical spring washer · Nut 7. Tighten: · Nut (primary pulley wheel) Primary pulley wheel nut 3, 3 m · kg NOTE: When the nut is tightened (primary pulley wheel), support the magnetic flywheel using the engine wheel support tool Engine wheel support tool 90890-01235 8. Adjust: · Trapezoidal belt Tense the trapezoidal belt by turning the primary pulley wheel several times 9. Install: · Fan Screw (fan) 0. 7 m · kg KICKSTART PEDAL 1. Install: · Return spring · Pedal axle · Bushing · Flat washer · Elastic circlip 4-33 ASSEMBLY AND ADJUSTMENT OF ENGINE 2. Install: · Crankcase cover Screw (crankcase cover) 7 Nm (0. 7 m · kg) 5. Install: · Kickstart pedal Kickstart pedal 0. 9 m · kg 4-34 ASSEMBLY AND ADJUSTMENT OF ENGINE PISTON, CYLINDER AND CYLINDER HEAD MOT Carburettor gasket Reed valve Gasket Cylinder head Cylinder head gasket Cylinder Cylinder seal Piston rings Piston k Piston pin 10 k Circlips 11 k Bearing 12 CLEARANCE FROM PISTON TO CYLINDER: 0. 034 ~ 0. 047 mm Limit: 0. 1 mm BETWEEN ENDS (INSTALLED): Top ring 0. 15 ~ 0. 35 mm Limit: 0. 60 mm Second ring 0. 15 ~ 0. 35 mm Limit: 0. 60 mm LATERAL CLEARANCE: Top ring 0. 03 ~ 0. 05 mm Limit 0. 10 mm Second ring 0. 03 ~ 0. 05 mm Limit 0. 10 mm SPARK PLUG MANUFACTURER/TYPE: NKG/BR7HS GAP BETWEEN ELECTRODES 0. 06 ~ 0. 7 mm 4-35 ASSEMBLY AND ADJUSTMENT OF ENGINE MOT PISTON AND PISTON PIN 1. Apply: · Engine oil (in the crankshaft bearing, big end bearing, small end bearing, piston pin, piston ring grooves and piston skirt areas. ) 2. Install: · Reed valve gasket · Reed valve · Carburettor gasket Carburettor gasket 0. 9 m · kg 3. Install: · Small end bearing · Piston · Piston pin · Piston circlips NOTE: · The arrow of the piston should point to the exhaust side. · Before installing the piston circlip, cover the crankcase with a towel or clean cloth so that the circlip and other materials do not accidentally fall into the crankcase. · Always use new piston circlips. CYLINDER AND CYLINDER HEAD 1. Check: · Piston rings NOTE: · Ensure that the ends of the rings are correctly coupled around the centring devices on the piston grooves. · Check that the manufacturers symbols or numbers printed on the rings are on the upper side of same. 4-36 ASSEMBLY AND ADJUSTMENT OF ENGINE 3. Install: · Cylinder MOT NOTE: Install the cylinder with one hand while compressing the piston rings with the other. 4. Install: · Cylinder head · Spark plug · Air protector NOTE: · The arrow "EX" from the cylinder head should point to the exhaust side. · Tighten the cylinder head positioning nuts in several steps, using a cris-cross pattern Cylinder head positioning screws 1. 4 m · kg spark plug 2. 0 m · kg 6. Install: · Central stand · Spring · Axle · Clasp · Rubber washer · Strap loop 7. Install: · Brake shoes · Flat washer · Rear wheel 4-37 ASSEMBLY AND ADJUSTMENT OF ENGINE MOT ASSEMBLY OF ENGINE When the engine is being assembled, reverse the removal procedure 1. Install: · Engine assembly bolt · Rear shock absorber bolt (lower) Engine assembly bolt 8. 4 m · kg Rear shock absorber bolt (lower) 1. 8 m · kg 2. [. . . ] · Place the switch "b" on position "c" or "d". · Check if there is a voltage (12 V) on the "Chocolate" or "Dark Green" cable of the bulb holder connector. SATISFIES THE SPECIFIED VALUE (12 V) The circuit is in good condition. Bulb and bulb holder · Check the bulb and bulb holder for continuity. [. . . ]