SERVICE MANUAL CONTENTS 1. INFORMATION 2. MAINTENANCE 3. ENGINE REMOVAL AND INSTALLATION 4. ENGINE FUEL SYSTEM 5. ENGINE LUBRICATION AND COOLING SYSTEM 6. ENGINE COMBUSTION SYSTEM 7. TRANSMISSION SYSTEM 8. STEERING SYSTEM 9. FRONT WHEEL SYSTEM 10. 11. 12. 13. REAR WHEEL SYSTEM FENDERS AND EXHAUST PIPE ELECTRICAL SYSTEM TROUBLE SHOOTING 1. INFORMATION 1.1 1.2 1.3 SAFTY NOTES SPECIFICATION 1.4 1.5 SERIAL NUMBER TORQUE VALUE 1.1 SAFETY GASOLINE Gasoline is extremely flammable and is explosive under certain condition. Do not smoke or allow sparks or flames in your work area. CARBON MONOXIDE Never run the engine in a closed area. The exhaust contains poisonous carbon monoxide gas that may cause loss of consciousness and lead to death. BATTERY ELECTROLYTE The battery electrolyte contains sulfuric acid. Protect your eyes, skin and clothing. If you contact it, flush thoroughly with water and call a doctor if electrolyte gets in your eyes. HOT PARTS Engine and exhaust pipe become very hot and remain hot for one hour after the engine is run. Wear insulated gloves before handling these parts. USED ENGINE/GEAR OIL Used engine oil and gear oil may cause skin disease if repeatedly contact with the skin for long periods. Keep out of reach of children. 1.2 NOTES All information, illustrations, directions and specifications included in this publication are base on the latest product information available at the time of approval for printing. JI-EE Dynamic Technology Industry Co., Ltd. reserves the right to make changes at any time without notice and without incurring any obligation whatever. No part of this publication may be reproduced without written permission. 2 1.3 SPECIFICATION ENGINE (for ViperST & YukonST in this service manual) Type Displacement Bore and Stroke Compression ratio Maximum Torque (Nm/rpm) Maximum Power (ps/rpm) Carburetor Ignition Starting Lubrication Transmission Two cycle air cooled 49.3 c.c. 40.0X39.2mm 6.8:1 4.5 Nm/6000rpm 3.8 ps/6000rpm Piston type Capacitor Discharge Electric and kick starter Forced pressure and wet sump Automatic (C.V.T. V-belt) Fr Neut .Rev CHASSIS Overall Length Overall Width Overall Height Seat Height Wheel base Ground Clearance Dry Weight Fuel Tank Capacity ViperST EXL-50 YukonST EXL-50 1750 mm 1010 mm 1065 mm 760 mm 1115 mm 120 mm 152 kg 4.5 Liters 1670 mm 940 mm 1040 mm 760 mm 1110 mm 120 mm 152 kg 4.5 Liters ViperST SUSPENSION Front Rear BRAKES Front Rear TIRES Front Rear PRESSURE Front Rear EXL-50 YukonST EXL-50 Single A-arm / Adjustable Shocks Swing Arm / Adjustable Shock Dual Mechanical drum Hydraulic Disc 20/6-10 20/10-9 ¡i psi (0.23 kgf/cm2)¡j 12(0.8) 12(0.8) 12(0.8) 12(0.8) COLORING Specifications subject to change without notice. 3 1.4 SERIAL NUMBER (For ViperST EXL-50 / YukonST EXL-50 in this service manual) The frame serial number is stamped on the front of the frame. The engine serial number is stamped on the left side of the crankcase. Frame serial number Engine serial number 4 .5 TORQUE VALUES (For EXL 50 in this service manual) STANDARD 5 mm bolt and nut 6 mm bolt and nut 8 mm bolt and nut 5 N.m (3.5 lbf.ft) 10 N.m (7.2 lbf.ft) 22 N.m (16 lbf.ft) 35 N.m (25 lbf.ft) 55 N.m (40 lbf.ft) 10 mm bolt and nut 12 mm bolt and nut ENGINE Cylinder head nut Spark plug Cylinder head bolt Alternator bolt 28 N.m (20.7 lbf.ft) 12 N.m (8.9 lbf.ft) 20 N.m (14.8 lbf.ft) 8 N.m (5.9 lbf.ft) FRAME Handlebar upper holder bolt Throttle housing cover screw Steering shaft nut Steering shaft holder bolt Wheel rim bolt Tie rod lock nut King pin nut Handlebar lower holder nut Front wheel bolt Front axle castle nut Front brake arm nut Rear brake arm nut Rear axle castle nut Rear wheel bolt Exhaust muffler mounting bolt Engine hanger bolt Rear axle holder bolt Swing arm pivot nut Rear shock absorber mounting nut 24 N.m (17.7 lbf.ft) 4 N.m (2.9 lbf.ft) 50 N.m (36.9 lbf.ft) 33 N.m (24 lbf.ft) 18 N.m (13.3 lbf.ft) 35 N.m (25.8 lbf.ft) 40 N.m (29 lbf.ft) 40 N.m (29.5 lbf.ft) 24 N.m (17.7 lbf.ft) 40-60 N.m (30-45 lbf.ft) 4 N.m (3.0 lbf.ft) 7 N.m (5.2 lbf.ft) 40-60 N.m (30-45 lbf.ft) 24 N.m (17.7 lbf.ft) 30 N.m (22.1 lbf.ft) 30 N.m ( 22 lbf.ft) 90 N.m (65 lbf.ft) 90 N.m (65 lbf.ft) 45 N.m (33 lbf.ft) 5 2. MAINTENANCE 2.1 MAINTENANCE DATA 2.2 MAINTENANCE SCHEDULE 2.3 FUEL TUBE 2.4 THROTTLE OPERATION 2.5 THROTTLE CABLE ADJUSTMENT 2.6 AIR CLEANER 2.7 SPARK PLUG 2.8 IDLE SPEED 2.9 DRIVE CHAIN 2.10 BRAKE SYSTEM 2.11 WHEELS AND TIRES 2.12 STEERING SYSTEM 2.13 TOE-IN 2.14 GEAR OIL 2.1 MAINTENANCE DATA SPECIFICATION SPARK PLUG: SPARK PLUG GAP: RECOMMENDED SPARK PLUGS: THROTTLE LEVER FREE PLAY: IDLE SPEED: BRAKE LEVER FREE PLAY: DRIVE CHAIN SLACK FRONT/REAR TIRE PRESSURE TOE-IN 0.6-0.7 mm NGK BPR7HS 5-10 mm 1800±100 rpm 15-25 mm 10-25 mm MIN 2 psi (12.5kpa) 5±10 mm TORQUE VALUES SPARK PLUG TIE-ROD LOCK NUT 25-30 N.m 35-43 N.m ENGINE OIL GEAR LUBRICATION OIL JASO FC Grade or same degree oil SAE 90 2.2 MAINTENANCE SCHEDULE The maintenance internals in the follow table is based upon average riding, conditions. Riding in unusually dusty areas, require more frequent servicing. (For ATV all serial in this service manual) INITIAL SERVICE (First week) REGULAR SERVICE (Every 30 operating days) EVERY YEAR I FUEL LINE THROTTLE OPERATION I I AIR CLEANER C SPARK PLUG I CARBURETOR IDLE SPEED I I I, L DRIVE CHAIN I, L BRAKE SHOE WEAR BRAKE SYSTEM I I NUT, BOLT, FASTENER I I WHEEL I I STEERING SYSTEM SUSPENSION SYSTEM C.V.T. AIR FILTER C GEAR OIL REVERSE GEAR OIL-RXL90R Note ­ I: Inspect and Clean, Adjust, Lubricate or Replace, if necessary C: Clean L: Lubricate R: Replace I I I R R 2.3 FUEL TUBE Inspect the fuel lines for deterioration, damage or leakage and replace if necessary. 2.4 THROTTLE OPERATION Inspect for smooth throttle lever full opening and automatic full closing in all steering positions. Inspect if there is no deterioration, damage or kinking in the throttle cable, replace it if necessary. Check the throttle lever, free play is 5-10 mm at the tip of the throttle lever. Disconnect the throttle cable at the upper end. Lubricate the cable with commercially lubricant to prevent premature wear. 2.5 THROTTLE CABLE ADJUSTMENT Slide the rubber cap of the adjuster off the throttle Housing, loosen the lock nut and adjust the free play of the throttle lever by turning the adjuster on the throttle housing. Inspect the free play of the throttle lever. 2.6 AIR CLEANER Unscrew the air cleaner cover screws. Pull out the air filter element from the air cleaner case. Wash the element in non-flammable solvent, squeeze out the solvent thoroughly. Let it dry. Soak the filter element in gear oil and then squeeze out the excess oil. Install the element into air cleaner carefully. 2.7 SPARK PLUG This spark plug located at the front of the engine. Disconnect the spark plug cap and unscrew the spark plug. Check the spark plug electrodes for wearness. Change a new spark plug if the electrodes and insulator tip appear unusually fouled or burned. Discard the spark plug if there is apparent wear or if the insulator is cracked or chipped. The spark plug gap shall keep in 0.6-0.7mm. Tighten the spark plug with 25-30 N.m With the sealing washer attached, thread the spark plug in by hand to prevent cross threading. 2.8 IDLE SPEED Connect an engine speed meter. Warm up the engine, 10 minutes are enough. Turn the idle-speed adjust screw on the carburetor to obtain the idle speed. "Turn in" (clockwise) will get higher speed. "Turn out" (counter clockwise) will get lower speed. IDLE SPEED: 1800±100 rpm 2.9 DRIVE CHAIN Inspect the chain slack. The standard is 10-25mm. Adjust the chain slack. Loose the lock bolts (4 pcs) then adjust the drive chain slack by turn the adjusting nut. Tighten the four lock bolts. When the drive chain becomes very dirty, it should be removed, cleaned and lubricated by specify lubricator. Using commercial chain lubricant to lubricate the drive chain. Clean the drive chain with kerosene and wipe it dry. Inspect the drive chain for possible wear or damage. Replace the chain, if it is worn excessively or damaged. Inspect the sprocket teeth, if it is excessive wear or damage, replace it. Inspect the chain-tensioned roller. Replace it, if necessary. 2.10 BRAKE SYSTEM Inspect the front brake lever and cable for excessive play or other damage. Replace or repair if necessary. Measure the free play of the brake lever at the end of the brake lever. The standard of free play is 15-25 mm. Inspect the rear brake lever and cable for excessive play or other damage. Replace or repair if necessary. Measure the free play of the rear brake lever at the end of the lever. The standard is 15-25 mm. BRAKE SHOE WEAR FRONT BRAKE Release the front wheel and inspect the brake lining thickness. Service Limit: 2.0mm(0.08 inch) If either lining is worn beyond the service limit, replace Both brakes shoes. 2.11 WHEELS AND TIRES Inspect the tire surfaces for cuts, nails or other sharp objects. Check the tire surfaces at cold tire condition. The standard of tire pressure is 1.2±0.3 psi. (0.8 kgf/cm2) 2.12 STEERING SYSTEM Check the free play of the steering shaft with the front wheels, turned straight ahead. When there is excessive play, inspect the tie-rod, kingpin bushing and ball joint. STEERING SHAFT HOLDER BUSHING Remove the front fender first. Remove the steering shaft holder and check the steering shaft bushing for wears or damage. If the bushing is worn or damaged, change a new one. Grease the steering shaft bushing and install the parts in the reverse order of removal. Torque: steering shaft holder bolt: 33 N.m (24 lbf.ft) 2.13 TOE-IN Let the vehicle on level ground and the front wheels facing straight ahead. Mark the centers of the tires to indicate the axle center height. Measure the distance between the marks. Toe-in: 5±10mm Carefully move the vehicle back, let the wheels have turned 180 °, so the marks on the tires are aligned with the axle center height. Measure the distance between the marks. Calculate the difference in the front and rear measurements. Torque: 35-43 N.m If the toe-in is out of standard, adjust it by changing the length of the tie-rods equally by turning the tie-rod while holding the ball joint. Tighten the lock nuts. 2.14 GEAR OIL Gear oil needs to be changed every year. There is a gear oil release bolt at the rear of engine. Unscrew this release bolt and can let the dirty oil flow out. The re-add oil hole is on the engine case beside gearbox. 3. ENGINE REMOVAL AND INSTALLATION 3.1 SERVICE INFORMATION 3.2 ENGINE REMOVAL 3.3 ENGINE INSTALLATION 3.1 ENGINE SHALL BE REMOVED IN THE CONDITIONS OF NECESSARY REPAIRMENT OR ADJUSTMENT TO THE TRANSMISSION AND COMBUSTION SYSTEM ONLY 3.2 ENGINE REMOVAL Remove the seat and rear fender. (Chapter 11) Remove the spark plug cap from the spark plug. Remove the exhaust pipe. Disconnect the carburetor cable by unscrew two screws on top of the carburetor. Take off oil pump cable from the oil pump control plate. Oil pump is under the right side of engine. Disconnect the wire connectors. There are three connectors for carburetor auto-choke, starter motor and generator respectively. Remove the drive chain cover. This is under the chain. Remove the drive chain retaining clip and master link, and remove the drive chain. Remove the three engine hanger nuts and bolts. Remove the engine from the right side of frame. 3.3 ENGINE INSTALLATION Engine installation is essentially the reverse order of removal. The torque of engine hanger bolt is 24-30 Nm Route the wires and cable in reverse order properly. POORLY UNPROPER ADJUSTMENT TO THE IDLE SPEED SCREW IGNITION MALFUNCTION FUEL/AIR MIXTURE RATIO NO GOOD AIR CLEANER DIRTY INSULATOR LEAKS FUEL TANK CAP BREATHING HOLE CLOGGED LEAN MIXTURE FUEL JET OF CARBURETOR CLOGGED FUEL TANK CAP BREATHING HOLE CLOGGED FUEL FILTER CLOGGED FUEL FLOWS IN THE TUBE UNSMOOTHLY FLOAT LEVEL IN CARBURETOR TOO LOW RICH MIXTURE FLOAT NEEDLE VALVE IN CARBURETOR FAULTY FLOAT LEVEL TOO HIGH AIR DUCT IN CARBURETOR IS CLOGGED AIR CLEANER DIRTY 4. ENGINE FUEL SYSTEM 4.1 FUEL TANK 4.2 CARBURETOR 4.1 FUEL TANK REMOVAL Remove the seat and rear fender. Disconnect the fuel line from the carburetor. Remove the fuel tank cap and front fender. Unscrew the fuel tank fixed bolts. Note: Keep gasoline away from flames or sparks. Wipe up spilled gasoline at once. 4.2 CARBURETOR REMOVAL Remove the air cleaner. Disconnect the fuel line and auto-choke electric wire. Unscrew the intake pipe mounting bolts at the carburetor then removes the carburetor. Note: Turn fuel cup on (off) position Remove the carburetor cap. Remove the throttle cable from the throttle valve while depressing the throttle valve spring. Remove the needle clip retainer, the jet needle and needle clip. Inspect the throttle valve and jet needle surface for wearness, scratches or dirt. DISASSEMBLY Unscrew the float chamber scr ...