User manual ETON VECTOR ST 250 - SERVICE MANUAL

CONTENTS GENERAL INFORMATION 1.Information................................................................2 2.Maintenance...............................................................6 3.Engine Removal & Installation.....................................14 ENGINE 4. Lubrication System...................................................16 5. Fuel System.............................................................23 6. Cylinder HEAD & Cylinder Valve.................................34 7. Cylinder & Piston......................................................50 8. V-Belt driving system................................................58 9. Transmission............................................................72 10. ACG & Start one way clutch......................................84 11. Crankcase & Crank..................................................93 12. Cooling System.....................................................101 CHASSIS 13.Steering & Suspension..............................................113 14. Front Wheel & Brake System..................................121 15. Rear Wheel & Brake System...................................127 16. Fenders & Exhaust Pipe.........................................136 17. Electrical System..................................................142 18. Trouble Shooting..................................................151 1 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. 1.3 SPECIFICATION ENGINE Type Displacement Bore and Stroke 4 Stroke¡A Single Cylinder, Water cooled 249c.c. 71 mm x 63 mm 2 Compression Maximum Hp Maximum Torque (Nm/rpm) Carburetor Ignition Starting Lubrication Transmission 10.6:1 19ps / 5600 22.3 Nm / 5500 DC-CDI Electric Auto oil injection Automatic (C.V.T. V-belt + Reverse) CHASSIS Overall Length Overall Width Overall Height Wheel base Ground Clearance Dry Weight Fuel Tank Capacity 1815mm 1062mm 1130mm 1193mm 150mm 225kg 12L SUSPENSION Front Rear BRAKES Front Rear TIRES Front Rear PRESSURE ¡i Front Rear Hydraulic Disc*2 Hydraulic Disc*1 21x7-10 22x10-10 psi ( kgf/cm2)¡j 12(0.8) 12(0.8) Double A-Arm & Adjustable Shocks Swing Arm & Adjustable Shock COLORING Specifications subject to change without notice. 3 1.4 SERIAL NUMBER 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. Side Frame serial number Engine serial number Frame serial number 4 1.5 TORQUE VALUES STANDARD ¡´ ¡´ ¡´ ¡´ ¡´ 5 mm bolt and nut 6 mm bolt and nut 8 mm bolt and nut 10 mm bolt and nut 12 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) 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 TUBLE 2.4 THROTTLE OPERATION 2.5 THROTTLE CABLE AJUSTMENT 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 2.1 MAINTENANCE DATA SPECIFICATION SPARK PLUG SPARK PLUG GAP RECOMMENDED SPARK PLUGS THROTTLE LEVER FREE PLAY IDLE SPEED BRAKE LEVER FREE PLAY DRIVE CHAIN SLACK TOE-IN 0.8 mm NGK CR8E 5-10 mm 1700¡Ó 100 rpm 15-25 mm 10-25 mm 5¡Ó 10 mm TORQUE VALUES SPARK PLUG TIE-ROD LOCK NUT ENGINE OIL GEAR LUBRICATION OIL 12-19 N.m 35-43 N.m 1.4 Liter (1.2Liter for change) 750cc (650cc for change) 6 2.2 MAINTENANCE SCHEDULE The internal maintenance in the following table is based on average riding, normal conditions. Riding in unusually dusty areas, require more frequent servicing. 300KM 1 Month I I I I I, L I I I I I I I R R I C I I I I I Every Every 1000KM 3000KM 3 Months 6 Months I I C R I I I R I I I I I R Replace for every 3,000km or 6 Months Replace for every 3,000km or 6 Months I,C I,C C I I R I I Every 6000 KM 1 Year Every 12000KM 2 Years R Notes Fuel Lines Throttle Operation Air Filter Fuel Filter Spark Plug Drive Chain Brake Shoes Brake System Brake Fluid Nuts, Bolts & Fasteners WHEEL/TIRES Wheels Steering System Suspension System C.V.T Drive belt Transmission Oil Engine Oil Battery Oil Filter (Screen) Valve Clearance Coolant Cooling Fan Carburetor (Idle Speed) Choke R R Lubricate for every 1 month Note ­ I: Inspect and Clean, Adjust, Lubricate or Replace, if necessary C: Clean L: Lubricate R: Replace 2.3 FUEL TUBE Inspect the fuel lines for deterioration, damaging or leakage and replace if necessary. 7 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 kink 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. Throttle 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 Please remove the four hooks, and then disassemble two screws inside the air cleaner case. Pull out the air filter element from the air cleaner case. Washing 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 every component into air cleaner in the reverse order of removal. Note: for more detail please check chapter 5-10 8 2.7 SPARK PLUG This spark plug is located at the front of the engine. Disconnect the spark plug cap and unscrew the spark plug. Check the condition of spark plug electrodes wear. 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 With the sealing washer attached, thread the spark plug in by hand to prevent crosses threading. Tighten the spark plug with 12-19 N.m 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: 1700±100 rpm 2.9 DRIVE CHAIN Stopping the ATV and shift the transmission into neutral(N) . Measure the drive chain slack midway between the sprockets. Chain slack =15~25mm (5/8~1 inch) Adjust the chain slack. Loosen the lock nuts and turn drive chain adjusting nuts until get the correct slack. Tighten the axle holder bolts. Torque = 90N.m (65 lbf.ft) 9 When the drive chain becomes very dirty, it should be removed, cleaned and lubricated by specify lubricator. Please use special chain oil to lubricate the drive chain. Clean the drive chain with kerosene and wipe it dry. Inspect the drive chain for any possible wearing or damaging. Replace the chain, if it is worn excessively or damaged. Inspect the sprocket teeth, if it is excessive wearing or damaging, please replace it. 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. Adjustable nut Brake level The parking brake is shown on the picture. The position of parking Off is on the left side. Turn parking brake to right side is parking on Parking Brake Parking Off Parking On 10 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 level Adjustment NOTE: The second method to adjust brake level is under the driver seat and rear brake component. Because the brake system is different, ones need to adjust it to reach a proper brake level. Rear Brake Front Brake Adjustable nut Parking Brake Adjustable nut 2.11 WHEELS AND TIRES Inspect the tire surfaces for cuts, nails or other sharp objects. Check the each tire surface at cold tire condition. *The standard of tire pressure is 12(0.8) psi ( kgf/cm2) 11 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, please 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 Keep 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. 12 Carefully to move the vehicle back, let the wheels turn 180 degree, 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. Toe-in: 5±10mm 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. Torque: 35-43 N.m Lock Nuts 13 3. ENGINE REMOVE AND INSTALLATION 3.1 REPAIR CONDITION 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 Before removing engine, you need to remove all of components such as seat, front and back fender, fuel tube, exhaust pipe, carburetor cable and drive chain...etc. You can then see three hanger bolts which have screwed on engine. Loosen these three hanger bolts. You have succeeded to remove this engine. There are some pictures to describe main step of removing engine. Disconnect the wire connectors. There are three connectors for carburetor auto-choke, starter motor and generator respectively. Remove the drive chain cover. Remove the drive chain retaining clip and master link, and remove the drive chain. Hanger bolt 14 Hanger bolt 3.3 ENGINE INSTALLATION The Engine installation is essentially in the reverse order of removal. The torque of engine hanger bolt is 30 N.m Route the wires and cable in reverse order properly. 15 4. LUBRICATION SYSTEM 4-1 Mechanism Diagram 4-2 Precautions in Operation 4-3 Troubleshooting 4-4 Engine Oil 4-5 Engine Oil Strainer Clean 4-6 Oil Pump 4-7 Gear Oil 4-1 Mechanism Diagram Valve Rocker Arm Press-In Lubrication Cam Shaft Oil Route Spray Lubrication Con-Rod Oil Route Spray Lubrication Press-In Lubrication Rotate Direction Oil Pump Oil Strainer 16 4-2 Precautions in Operation General Information: This chapter contains maintenance operation for the engine oil pump and gear oil replacement. Specifications Engine oil quantity Oil viscosity Gear oil Disassembly: 1400 c.c. Change: 1200c.c. SAE 10W-30 (Recommended King serial oils) Disassembly: Change: 750c.c. 650c.c. Gear oil viscosity SAE 140 (Recommended SYM Hypoid gear oils) ³æ¦ì Items Inner rotor clearance Oil pump Clearance between outer rotor and body Clearance between rotor side and body :mm Limit (mm) 0.20 0.25 0.12 Standard (mm) 0.15 0.15~0.20 0.04~0.09 Torque value Torque value oil strainer cap Engine oil drain bolt Gear oil drain bolt Gear oil join bolt Oil pump connection bolt 1.5~3.0kgf-m 1.9~2.5kgf-m 1.0~1.5kgf-m 1.0~1.5kgf-m 0.8~1.2kgf-m 4-3 Troubleshooting Low engine oil level Oil leaking Valve guide or seat worn out Piston ring worn out Dirty oil No oil change in periodical Cylinder head gasket damage Piston ring worn out Low oil pressure Low engine oil level Clogged in oil strainer, circuits or pipes Oil pump damage 17 4-4 Engine Oil Turn off engine, and park the ATV in flat surface with main stand. Check oil level with oil dipstick. So not screw the dipstick into engine as checking. If oil level is nearly low level, fill out recommended oil to upper level. Oil Change Caution Drain oil as engine warmed up so that makes sure oil can be drained smoothly and completely. Place an oil pan under the ATV, and remove oil drain bolt. After drained, make sure washer can be re-used. Install oil drain bolt. Torque value¡G 1.9~2.5kgf-m Drain bolt 4-5 Engine Oil Strainer Clean Drain engine oil out. Remove oil strainer and spring. Clean oil strainer. Check if O-ring can be re-used. Install oil strainer and spring. Install oil strainer cap. Torque value¡G 1.5~3.0kgf-m Add oil to crankcase (oil viscosity SAE 10W-30) Recommended using King serial oil. Engine oil capacity: 1200c.c. when replacing Install dipstick, start the engine for running several minutes. Turn off engine, and check oil level again. Check if engine oil leaks. Oil strainer cap O-ring Oil strainer 18 4-6 Oil Pump Oil Pump Removal Remove generator and starting gear. (Refer to chapter 10) ¡C Remove cir clip and take out oil pump driving chain and sprocket. Clip Make sure that pump shaft can be rotated freely. Remove 2 screws on the oil pump, and then remove oil pump. 2 screws Oil Pump Disassembly Remove the screws on oil pump cover and remove the cover. Remove oil pump shaft roller and shaft. 1 screw Roller 19 Oil Pump Inspection Check the clearance between oil pump body and outer rotor. Limit: 0.25 mm Check clearance between inner and outer rotors. Limit: 0.20 mm Check clearance between rotor side face and pump body Limit: 0.12 mm Oil Pump Re-assembly Install inner and outer rotors into the pump body. Align the indent on driving shaft with that of inner rotor. Install the oil pump shaft and roller. Install the oil pump cover and fixing pins properly. Pins 20 Tighten the oil pump screw. 1 screw Roller Oil Pump Installation Install the oil pump, and then tighten screws. Torque value¡G 0.8~1.2kgf-m Make sure that oil pump shaft can be rotated freely. 2 screws Install oil pump drive chain and sprocket, and then install cir clip onto oil pump shaft. Clip Install starting gear and generator. (Refer to chapter 10) 21 4-7 Gear Oil Gear Oil Change Remove oil join bolt. Remove drain bolt and drain gear oil out. Install the drain bolt after drained. Torque value: 1.0~1.5kgf-m Make sure that the drain bolt washer can be re-used. Add oil to specified quantity from the join hole. Gear Oil Quantity: 650c.c. when replacing Make sure that the join bolt washer can be re-used, and install the bolt. Start engine and run engine for 2-3 minutes. Turn off engine and make sure that oil level is in correct level. Make sure that no oil leaking. Gear oil join bolt Gear oil drain bolt 22 5. FUEL SYSTEM 5-1 Mechanism Diagram 5-2 Precautions in Operation 5-3 Trouble Diagnosis 5-4 Carburetor Remove / Install 5-5 Air Cut-Off Valve 5-6 Throttle Valve 5-7 Float Chamber 5-8 Adjustment of Idle Speed 5-9 Fuel Tank 5-10 Air Cleaner 5-1 Mechanism Diagram Fuel tank cap Fuel unit Fuel tank Auto fuel cock Carburetor Fuel strainer Inlet pipe 23 5-2 Precautions in Operation General Information Warning Gasoline is a low ignition point and explosive materials, so always work in a well-ventilated place and strictly prohibit flame when working with gasoline. Cautions Do not bend off throttle cable. Damaged throttle cable will make unstable drive-ability. When disassembling fuel system parts, pay attention to O-ring position, replace with new one as re-assembly There is a drain screw in the float chamber for draining residual gasoline. Do not disassemble air cut valve arbitrarily. Tool Special service tools Vacuum/air pressure pump Fuel level gauge Specification of CARBURETOR ITEM Carburetor diameter I.D. number Fuel level Main injector Idle injector Idle speed Throttle lever clearance Air screw UA25A Ø22mm PTG 050 14.8mm # 110 # 35 1700 ± 100rpm 1~3 mm 2 turns 24 5-3 Trouble Diagnosis Poor engine start No fuel in fuel tank Clogged fuel tube Too much fuel in cylinder No spark from spark plug(malfunction of ignition system ) Clogged air cleaner Malfunction of carburetor chock Malfunction of throttle operation Mixture too lean Clogged fuel injector Vacuum piston stick and closed Malfunction of float valve Fuel level too low in float chamber Clogged fuel tank cap vent Clogged fuel filter Obstructed fuel pipe Clogged air vent hose Air existing in intake system Stall after started Malfunction of carburetor chock Incorrect ignition timing Malfunction of carburetor Dirty engine oil Air existing in intake system Incorrect idle speed Mixture too rich Clogged air injector Malfunction of float valve Fuel level too high in float chamber Malfunction of carburetor chock Dirty air cleaner Rough idle Malfunction of ignition system Incorrect idle speed Malfunction of carburetor Dirty fuel Intermittently misfire as acceleration Malfunction of ignition system Late ignition timing Malfunction of ignition system Malfunction of carburetor Power insufficiency and fuel consuming Fuel system clogged Malfunction of ignition system 25 5-4 Carburetor Remove / Install Removal Drain out fuel in the float chamber. Drain bolt Loosen the choke cable fixed iron sheet screw from plate. Remove the choke cable. 1 screw Choke cable Vacuum pipe Fuel pipe Disconnect the fuel hose. Release the clamp strip of air cleaner. Clamp Remove the carburetor upper parts from the carburetor. Release the 2 nuts of carburetor insulator, and then remove the carburetor. Installation Install in reverse order of removal procedures. 2 nuts 26 5-5 Air Cut-Off Valve Disassembly Remove 2 screws. 2 screws Remove air cut-off valve cover, spring and valve. O-ring Spring Air cut-off valve Cover Inspection Check the valve is in normal. If the valve is in normal, it will restrict air-flow. If air-flow is no restricting, replace carburetor assembly. Check the vacuum pipe o-ring is in normal. Assembly Install in reverse order of removal procedures. 27 5-6 Throttle Valve Disassembly Remove carburetor upper parts, and then remove throttle valve and throttle cable. Throttle valve Disconnect the throttle cable from the throttle valve and remove the valve spring. Remove the fuel needle clamp and fuel needle. Spring Assembly Place the fuel needle onto the throttle valve and clip it with needle clamp. Install the sealed cap, carburetor upper part, and throttle valve spring. Connect the throttle valve cable to the throttle valve. Install the throttle valve into the carburetor body. Needle clamp Fuel needle clip Throttle cable Fuel needle Caution Align the groove inside the throttle valve with the throttle stopper screw of the carburetor body. Tighten the carburetor upper part. Adjust the free play of throttle valve cable. 28 5-7 Float Chamber Disassembly Remove 3 mounting screws and remove float chamber cover. 3 Screws Remove the fuel level plate, float pin, float and float valve. Float Float valve Fuel level plate Pin Inspection Check float valve and valve seat for damage, blocking. Check float valve for wearing, and check valve seat face for wear, dirt. Pin Caution In case of worn out or dirt, the float valve and valve seat will not tightly close causing fuel level to increase and as a result, fuel flooding. A worn out or dirty float valve must be replaced with a new a new one. Float Float valve Check for wear or damage 29 Remove main jet, needle jet holder, needle jet, slow jet and air adjustment screw. Needle jet holder Main jet Caution Take care not to damage jets and adjust screw. Before removing adjustment screw, turn it all the way down and note the number of turns. Does not turn adjust screw forcefully to avoid damaging valve seat face. Clean jets with cleaning fluid. Then use compressed air to blow the dirt off. Blow carburetor body passages with compressed air. Needle jet Slow jet Assembly Install main jet, needle jet holder, needle jet, slow jet and air adjustment screw. Caution Set the air adjustment screw in according to number of turns noted before it was removed. Install the float valve, float, and float pin. Air adjustment screw Checking fuel level Caution Check again to ensure float valve, float for proper installation. To ensure correct measurement, position the float meter in such a way so that float chamber face is vertical to the main jet. Fuel level: 14.8mm Float gauge Installation of carburetor Install carburetor in the reverse order of removal. Following adjustments must be made after installation. £» Throttle cable adjustment. £» Idle adjustment Lock nut Throttle adjustment screw 30 5-8 Adjustment of Idle Speed Caution Air screw was set at factory, so no adjustment is needed. Note the number of turns it takes to screw it all the way in for ease of installation. The parking brake must be used to stop the ATV to perform the adjustments. Use a tachometer when adjusting engine RPM. Screw in air adjustment screw gently, then back up to standard turns. Standard turns: 1 1/2turns Warm up engine; adjust the throttle stopper screw of throttle valve to standard RPM. Idle speed rpm: 1700 ± 100 rpm Connect the hose of exhaust analyzer to exhaust front end. Press test key on the analyzer. Adjust the pilot screw and read CO reading on the analyzer CO standard value: 1.0~1.5 % Accelerate in gradual increments; make sure rpm and CO value are in standard value after engine running in stable. If rpm and CO value fluctuated, repeat the procedures described above for adjusting to standard value. Parking brake Throttle valve stopper screw Air adjustment screw 31 5-9 Fuel Tank Fuel unit removal Open the seat. Remove the front cover and fuel tank. Remove the side covers and lower side covers. Remove the front fender. (Covers remove please refer chapter 13) Disconnect fuel unit coupler. Remove fuel unit (4 bolts). 4 bolts Caution Do not bend the float arm of fuel unit £» Do not fill out too much fuel to fuel tank. Fuel unit inspection (Refer to electrical equipment chapter 17). £» Coupler Fuel unit installation Install the gauge in the reverse order of removal. Caution Do not forget to install the gasket of fuel unit or damage it. Fuel tank removal Open the seat. Remove the front cover and fuel tank. Remove the side covers and lower side covers. Remove the front fender. (Covers remove please refer chapter 13) Disconnect fuel unit coupler. Remove fuel unit (4 bolts). Remove the fuel tube. Remove the vacuum tube. Vacuum tube Fuel tube Remove fuel tank front and rear side 4 bolts, and then remove fuel tank. FRONT Installation Install the tank in the reverse order of removal. REAR 4 bolts 32 5-10 Air Cleaner Removal Loosen the clamp strip of air cleaner and carburetor, and then remove the vapor hose. Clamp Loosen the clamp strip of air cleaner, and then remove the air cleaner vapor hose. Remove the air cleaner (4 bolts). Installation Install the tank in the reverse order of removal. Clamp 4 bolts Cleaning air cleaner element Remove the air cleaner cover (4 catch hooks). 4 hooks Remove element mounting screw. Loosen the clamp strip of air cleaner element, and then remove the air cleaner element. Clean the element with non-flammable or high-flash point solvent and then squeeze it for dry. Clamp 1 screw Caution Never use gasoline or acid organized solvent to clean the element. Soap the element into cleaning engine oil and then squeeze it out. Install the element onto the element seat and then install the air cleaner cover. 33 6. CYLINDER HEAD/VALVE 6-1 Mechanism Diagram 6-2 Precautions in Operation 6-3 Troubleshooting 6-4 Cylinder Head Removal 6-5 Cylinder Head Inspection 6-6 Valve Stem Replacement 6-7 Valve Seat Inspection and Service 6-8 Cylinder Head Reassembly 6-9 Cylinder Head Installation 6-10 Valve Clearance Adjustment 6-1 Mechanism Diagram 1.0~1.4kgf-m 1.0~1.4kgf-m 3.6~4.0kgf-m 2.4~3.0kgf-m 1.0~1.4kgf-m 1.0~1.4kgf-m 1.0~1.2kgf-m 0.7~1.1kgf-m 1.0~1.4kgf-m 1.0~1.2kgf-m 34 6-2 Precautions in Operation General Information This chapter is contained maintenance and service for cylinder head, valve, and camshaft as well as rocker arm. Cylinder head service can be carried out when engine is in frame. Specification of CYLINDER HEAD Item Compression pressure Camshaft Height of cam lobe ID of valve rocker arm OD of valve rocker arm shaft OD of valve stem ID of valve guide Clearance between valve stem and guide Valve Free length of valve spring Valve seat width Valve clearance Tilt angle of cylinder head Intake Exhaust Intake Exhaust Intake Exhaust Intake Exhaust Intake Exhaust Standard 12±2 kg/cm2 5.90 5.70 11.982~12.000 11.966~11.984 4.975~4.990 4.950~4.975 5.000~5.012 0.010~0.037 0.025~0.062 38.700 40.400 3.400 0.10±0.02mm 0.15±0.02mm --Limit --5.85 5.65 12.080 11.936 4.900 4.900 5.030 0.080 0.100 35.200 36.900 4.000 0.050 Rocker arm Torque Value Cylinder head cover bolt Exhaust pipe stud bolt Cylinder head bolt Cylinder head Nut Sealing bolt of cam chain auto-tensioner Bolt of cam chain auto-tensioner Cylinder side cover bolt Cam sprocket bolt Tappet adjustment screw nut Spark plug 1.0~1.4kgf-m 2.4~3.0kgf-m 1.0~1.4kgf-m 3.6~4.0kgf-m 0.8~1.2kgf-m 1.2~1.6kgf-m 1.0~1.4kgf-m 1.0~1.4kgf-m 0.7~1.1kgf-m 1.0~1.2kgf-m Tools Special service tools Valve reamer: 5.0mm Valve guide driver: 5.0mm Valve spring compressor 35 6-3 Troubleshooting Engine performance will be affected by troubles on engine top parts. The trouble usually can be determined or by performing cylinder compression test and judging the abnormal noise generated. Low compression pressure 1. Valve Improper valve adjustment Burnt or bent valve Improper valve timing Valve spring damage Valve carbon deposit. 2. Cylinder head Cylinder head gasket leaking or damage Tilt or crack cylinder 3. Piston Piston ring worn out. High compression pressure Too much carbon deposit on combustion chamber or piston head Noise Improper valve clearance adjustment Burnt valve or damaged valve spring Camshaft wear out or damage Chain wear out or looseness Auto-tensioner wear out or damage Camshaft sprocket Rocker arm or rocker arm shaft wear out 36 6-4 Cylinder Head Removal Remove engine. (Refer to chapter 5) Remove the inlet pipe (2 nuts). 2 nuts Remove 1 bolt of thermostat and then remove the thermostat. Remove hole bolt and spring for the cam chain tensioner. Loosen 2 bolts, and then remove tensioner. Remove thermostat (2 bolts). Thermostat bolts Tensioner bolts Remove Air Injection system (AI) pipe mounting bolts. Remove spark plug. 4 bolts Spark plug Remove the side cover mounting blots of cylinder head, and then take out the side cover. 3 bolts 37 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 Remove cam shaft setting plate (1 bolt). Cam shaft setting plate Remove rocker arm shafts and rocker arms. Special Service Tool: Rocker arm and cam shaft puller Rocker arm shafts Rocker arm shaft and cam shaft puller Remove cam shafts. Special Service Tool: Rocker arm and cam shaft puller Cam shafts Rocker arm shaft and cam shaft puller 38 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 2 bolts Remove cylinder head gasket and 2 dowel pins. Remove chain guide. Clean up residues from the matching surfaces of cylinder and cylinder head. Gasket Caution Do not damage the matching surfaces of cylinder and cylinder head. Avoid residues of gasket or foreign materials falling into crankcase as cleaning. Chain guide Dowel pins 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 Valve cotter remove and assembly tool Inlet valve Inner spring Spring retainer Exhaust valve Outer spring Cotter 39 Remove valve stem seals. Valve stem seals Clean carbon deposits in combustion chamber. Clean residues and foreign materials on cylinder head matching surface. Caution Do not damage the matching surface of cylinder head. 6-5 Cylinder Head Inspection Check if spark plug and valve holes are cracked. Measure cylinder head warp with a straightedge and thickness gauge. Service limit: 0.5 mm Camshaft Inspect cam lobe height for damaged. Service Limit: IN: Replacement when less than 34.45mm EX: Replacement when less than 34.30mm Inspect the camshaft bearing for looseness or wear out. If any damage, replace whole set of camshaft and bearing. 40