Vento Triton R4, Service Maintenance Manual

Page 1: ...VENTO MOTORCYCLES Rev no 01 Page 1 of 143 Triton R4 Service Maintenance Manual ...

Page 2: ...VENTO MOTORCYCLES Rev no 01 Page 2 of 143 ...

Page 3: ...ual contains an introductory description on VENTO Triton R4 and procedures for Inspection Service and overhaul of its main components This Manual is intended those who have enough knowledge and skills for servicing of VENTO vehicles Without such knowledge and skills you should not attempt servicing by relying on this manual only Instead please contact your nearly authorized VENTO motorcycle dealer...

Page 4: ...VENTO MOTORCYCLES Rev no 01 page 4of 143 ...

Page 5: ...O MOTORCYCLES Rev no 01 page 5of 143 GENERAL INFORMATION MODEL IDENTIFICATION 1 1 FUEL AND ENGINE OIL 1 1 BREAK IN PROCEDURES 1 1 PRECAUTIONS AND GENERAL INSTRUCTIONS 1 2 SPECIFICATIONS 1 3 CONTENTS 1 1 1 1 ...

Page 6: ...this scooter Make sure that the Engine oil Gear oil what you are using should come under API classification BREAK IN PROCEDURES During manufacture only the best possible materials are used and all machined parts are finished to a very high standard but it is still necessary to allow the moving parts to BREK IN before subjecting the engine to maximum stresses The future performance and reliability ...

Page 7: ...ng a circlip always ensure that it is completely seated in its groove and securely fitted o Do not use self locking nuts a few times over o If parts replacement is necessary replace the parts with VENTO Genuine parts or their equivalent o When removing parts that are to be reused keep them arranged in an orderly manner so that they may be reinstall in proper order and orientation o Always use spec...

Page 8: ...g system Electric and kick start Lubricating system Lubrication by oil pump ELECTRICAL Ignition System Electronic CDI Ignition Timing 150 at 5000 RPM Spark Plug NGK R BR8HSA Storage Battery Yuasa YTX5L BS Battery Capacity 12V 4Ah Magneto AC Fuse 8Amp Headlight 12V 35 35 Watt Turn Indicators X4 12V 10 Watt Tail light stop light 12V 5Watt Meter light 12V 1 7Watt Oil level Indicator light 12V 1 7 Wat...

Page 9: ...stment procedures 2 2 Storage battery 2 2 Cylinder head nut and exhaust pipe bolt 2 3 Cylinder head and cylinder 2 3 Spark plug 2 4 Fuel level line 2 4 Air cleaner 2 5 Throttle cable 2 5 Engine idle speed 2 5 Oil pump 2 6 Gear oil 2 7 Braking 2 7 Tire 2 10 Steering 2 10 Front shock absorber 2 11 Vehicle bolts and nuts 2 11 2 CONTENT SS ...

Page 10: ...10000 Interval Months 2 12 24 36 48 Storage battery I I I I I Cylinder head nut and exhaust pipe bolt T T T T T Cylinder head and cylinder C C C C Spark plug C R C R Air cleaner Inspect Clean every 3000 Kms 1890 miles Replace every 10000 Kms 6300 Miles Idle speed rpm I I I I I Throttle cable play I I I I I Oil pump I I I I I Gear oil R R R R R I I I I I Fuel line Replace every 4 years Brake I I I ...

Page 11: ...tially 1000Kms 630 miles 2 months and every 6000 Kms 3780 miles 12 months Open the battery box cover from the foot rest Disconnect Negative terminal Cable first then Positive terminal Cable of Battery Measure the voltage between the ve and ve terminal of Battery charge the Battery if the voltage is below the specified limit BATTERY TESTING PROCEDURE ...

Page 12: ...pection if the battery on the vehicle is found defective before replacing with a new battery it is important to check the battery charging circuit BATTERY CHARGING CIRCUIT TEST The MAGNETO generated AC current which is rectified into DC current by Voltage Regulator It is automatically charging the battery depending upon condition of the battery load and engine rpm Regulator is connected in paralle...

Page 13: ...tery 8 12 hrs For old battery 12 14 hrs WARNING Always open all the caps of battery before charging Keep flames sparks away from the battery Turn ON or OFF Switch at charger not at battery terminal Don t charge the battery if electrolyte temperature is more than 45ºC Do not quick charge the battery INSTALLATION Connect positive terminal first then negative terminal BATTERY CAPACITY 12Volt 4Ah YB4L...

Page 14: ...ers 2 Remove the cylinder head cover bolt 3 Remove spark plug Suppressor cap 4 Tighten the nuts evenly one by one to the specified torque Tighten the nuts in the Specified order Tightening Torque Cylinder head nut 15 18N m Exhaust pipe bolt 15 18N m Cylinder and cylinder head Remove carbon every 6000 km 3780 miles or 12 months Carbon deposits in the combustion chamber and the cylinder head will ra...

Page 15: ...ically CARBON DEPOSIT Check to see the carbon deposit on the Spark Plug If the carbon is deposited remove it with a spark plug cleaner machine or carefully using a tool with a pointed end Check to see the worn out or burnt condition of the electrodes If it is extremely worn or burnt replace the plug and also replace the plug if it has a broken insulator damaged thread etc Thickness gauge Spark plu...

Page 16: ...t between the palms of both hands do not twist or wring the air cleaner element or it will develop tears Immerse cleaned filter element in CCI or CCI Super oil and Squeeze the oil out of the element leaving it slightly wet With oil Fit the element to the Air cleaner case properly Install Air cleaner in the reverse order of removal CAUTION Before and during the cleaning operation inspect the core f...

Page 17: ...ereafter Adjust the throttle cable play warm up the engine at normal running condition NOTE A warm engine means an engine that has been run for 10 minutes 1 Connect a Digital Tachometer to the connecting portion of the magneto lead wire as shown In the illustration Use the selector key C position Adjust the Idling Screw 1 to obtain the Idling RPM as follows Idling Speed 1800 100 RPM Finally adjust...

Page 18: ... controlled by amount of throttle opening Check the oil pump in the following manner to confirm correct operation for Throttle valve full opening position Turn the throttle grip full open Check whether mark on the oil pump control lever s aligned with the index mark when the throttle valve is positioned as above If the marks are not aligned loosen lock nuts and turn the adjuster in or out to align...

Page 19: ...every 6000 km 4000 miles 12 months thereafter replace brake fluid after every 2 years replace brake hose after every 4 years Front brake fluid level Keep the scooter upright and place the handlebar straight Check brake fluid level by observing the lower limit line on the brake fluid reservoir When the level is below the lower limit line replenish with Brake fluid that meets the following specifica...

Page 20: ...e pressure developed by the master cylinder and thus interferes with the full braking performance of the brake caliper The presence of air is indicated by sponginess of the brake lever and also by lack of braking force Considering the danger to which such trapped air exposes the machine and rider it is essential that after remounting the brake and restoring the brake system to the normal condition...

Page 21: ...uid flowing into the receptacle no longer contains air bubbles NOTE When bleeding the braking system replenish the brake fluid reservoir if necessary Make sure that there is always some fluid visible in the reservoir Close the bleeder valve disconnect the pipe Fill the reservoir with specified brake fluid to the UPPER end of the inspection window TIGHTENING TORQUE BLEEDER VALVE 6 9N m 0 6 0 9kg m ...

Page 22: ...Indicator on the rear brake Inspect brake lining limit as follows First check if the brake system is properly Adjusted When operating the brake check to see that the tip of indicator is within the range If the tip of indicator is beyond the range the brake shoe assembly should be replaced with a new set of shoe ...

Page 23: ...oter with the excessively worn tires will decrease riding stability and consequently invite dangerous situation It is highly recommended to replace the tire when the remaining depth of tire tread reaches the following specification Tire Tread depth limit 1 6 mm 0 064 Inch Use Tire depth gauge STEERING Steering should be adjusted properly for smooth turning of handlebars and safe running Over tight...

Page 24: ... 630 miles 2 months and every 6000 km 3780 miles 12 months thereafter These bolts and nuts listed below are important safety components They must be Specified tightening torque No Description N m Kg m 1 Front axle nut 55 60 5 5 6 2 Handle tightening nut 37 44 3 7 4 4 3 Steering stem locknut 37 44 3 7 4 4 4 Disc brake caliper fixing bolt 22 29 2 2 2 9 5 Disc brake master cylinder hose fixing bolt 2...

Page 25: ...VENTO MOTORCYCLES Rev no 01 page 25of 143 10 14 14 ...

Page 26: ... stuck in grooves Ruptured or otherwise defective cylinder head gasket COMPRESSION PRESSURE TESTING PROCEDURE NOTE Before testing the engine for compression pressure make sure that the cylinder head nuts are tightened to the specified torque values Have the engine warmed up Idling before testing Be sure that the battery used is in fully charged condition Remove the parts concerned and test the com...

Page 27: ...done 1 INITIAL ENGAGEMENT INSPECTION Warm up the engine to its normal running temperature Connect the digital tachometer Seated on the motorcycle on the level ground increase the engine RPM slowly and note the RPM at which the motorcycle begins to move forward ENGAGEMENT RPM 2700 3100 RPM 2 CLUTCH LOCK UP INSPECTION Perform this inspection to determine if the clutch is engagement and not slipping ...

Page 28: ... disassembly Engine components inspection and servicing Bearings Oil seals Crankshaft Automatic clutch inspection Cylinder head Cylinder Piston Reed valve Engine remounting Oil seals Bearings Bushings Crankcase Rear axle shaft Transmission Starter pinion and starter gear Movable driven and clutch Movable drive Kicking starter Piston Oil pump and oil pump driven gear Intake pipe Magneto ...

Page 29: ...ame Engine left side Kick starter lever Clutch cover Kick starter shaft Kick driven gear Fixed drive fan Fixed drive gear B belt Movable drive face Starter driven gear Starter drive gear Clutch housing Gear case cover Transmission gear Clutch shoe Engine center Intake pipe Reed valve Oil pump Oil pump gear Cylinder head Cylinder Piston Engine right side Cooling fan Magneto Starter motor ...

Page 30: ...EINSTALLATION ENGINE ASSY Remove the muffler Remove cooling fan cover Remove cylinder cover Remove cooling fan Remove magneto nut with special tools Remove magneto rotor and half circle key with special tools Remove magneto stator and paper gasket Remove oil pump ...

Page 31: ... 31of 143 Remove worm wheel and oil seal press board Remove cylinder head and cylinder Place a cloth stopper below the piston and remove the circlip with a plier Remove the piston pin and piston Remove the piston rings from the piston ...

Page 32: ...VENTO MOTORCYCLES Rev no 01 page 32of 143 Remove the kick starter lever Remove side cover Remove movable ratchet wheel and clip ...

Page 33: ...o 01 page 33of 143 Remove starting driven ratchet wheel by removing the nuts Remove fan 5 and V belt 6 Disassemble the movable drive Face 7 Remove electric gear press board electric gear and super clutch Remove starter motor ...

Page 34: ...VENTO MOTORCYCLES Rev no 01 page 34of 143 Remove the clutch housing with the special tool Drain gear oil Remove rear axle nut Remove rear wheel Remove brake shoe 5 and rear axle 6 ...

Page 35: ...emove the rear brake cam lever 1 indicator plate 2 and camshaft 3 Remove spring 4 Remove cotter pin 5 and shaft 6 Remove main stand 7 Remove gear case cover Remove paper gasket 1 and middle gear assy 2 Remove output gear assy 3 Remove carburetor ...

Page 36: ...VENTO MOTORCYCLES Rev no 01 page 36of 143 Remove intake pipe Remove reed valve and paper gasket Disassemble crankcase with special tools ...

Page 37: ...VENTO MOTORCYCLES Rev no 01 page 37of 143 Remove crankcase with special tools Remove crank shaft from crankcase Remove crankshaft bearing with special tools ...

Page 38: ...ile holding down clutch shoe assy By both hands as shown in the illustration WARNING Gradually back off the clutch shoe assy pressed down by hands to reduce the clutch sparing load Releasing the hand suddenly may cause the following parts to fly apart Clutch shoe nut 1 Clutch shoe assembly 2 Spring 3 CAUTION ...

Page 39: ...erwise the clutch shoe may be damaged Remove the movable driven face seat with a thin bared screwdriver Remove the pins 4 movable driven face 5 and fixed driven face 6 Remove circlip 1 Remove bearing with special tool Remove bearing with special tool CAUTION Replace the removed bearing with a new ...

Page 40: ...e spacer Remove the oil seal from the gear case cover with the special tool CAUTION Replace the removed oil seal with a new one Remove the bearing with special tool CAUTION Replace the removed bearing with a new one Removing the bearings with special tools ...

Page 41: ...seal with the special tools CAUTION Replace the removed oil seal with a new one Remove the bearing with special tool CAUTION Replace removed bearing with a new one Remove the drive shaft bearing 1 and idle shaft bearing 2 CAUTION The removed bearings should be replaced with new ones ...

Page 42: ...ing with the special tool CAUTION The removed bearing should be replace with a new one Remove the left crankshaft bearing with special tool CAUTION The removed bearing should be replaced with a new one BUSHING INSPECTION Inspect the bushing for wear or damage If any defects are found replace the bushing With a new one CRANKCASE BUSHING DISASSEMBLY Use two steel tubes of appropriate size to press ...

Page 43: ...s ENGINE COMPONENTS INSPECTION AND SERVICING BEARING Clear bearing with solvent and lubricate with engine oil before inspection Rotate the bearing inner race by finger to inspect for abnormal play noise and smooth rotation while the bearings are in the crankcase Replace the bearing if there is anything unusual ...

Page 44: ...mit Service limit 0 05mm 0 002in Excessive crankshaft run out is often responsible for abnormal engine vibration Such vibration reduces the engine life CONROD DEFLECTION AND CONROD BIG END SIDE CLEARANCE Turn the crankshaft with the connecting rod to feel the smoothness of rotary motion in the big end Move the rod up and down while holding the crankshaft rigidly to be sure that there is no rattle ...

Page 45: ...f the engine RPM doesn t coincide with the specified RPM range then disassemble and inspect the clutch Clutch shoe Inspect the shoes visually for chips cracking uneven wear and burning and check the thickness of the shoes with venire calipers If the thickness is less than the following service limit replace the complete assembly as a set Service limit 2 0mm 0 08 In CLUTCH HOUSING INSPECTION Clutch...

Page 46: ...aration or contamination with oil Measure the drive belt width with a venire calipers Replace it if the belt width is less than the service limit or and defect has been found Service limit 16 0mm 0 630in CAUTION Always keep the drive belt away from any greasy material MOVABLE DRIVE FACE INSPECTION Inspect the belt contact surface of the drive face for wear scratches or any abnormality if there is ...

Page 47: ...the service limit replace the spring with a new one Service limit 104 5mm 4 11 In Driven face pin and oil seal inspection Turn the driven face and check to see that the driven faces turn smoothly If any stickiness or hitches are found visually inspect the lip of oil seal driven face sliding surface and sliding pins for wear or damage Driven face Inspection ...

Page 48: ...VENTO MOTORCYCLES Rev no 01 Page 53 of 143 Inspect the belt contacting surface of both driven faces for any scratches wear and damage Replace driven face with a new one if there is any abnormality ...

Page 49: ...n the surface plate in a lapping manner The surface must be smooth and perfectly flat in order to secure a tight join a leaky joint can be the cause of reduced power output and increased fuel consumption CYLINDER Dearborn exhaust port and upper part of the cylinder taking care not to damage the cylinder wall surface The wear of the cylinder wall is determined from diameter reading taken at 20mm fr...

Page 50: ...ng machine to the next oversize PISTON Cylinder and piston clearance Cylinder piston clearance is the difference between piston diameter and cylinder bore diameter Be sure to take the marked diameter at right angles to the piston pin The value of elevation A is prescribed to be 20mm from the skirt end Service limit 39 885mm 1 5703In Measuring Instrument Micrometer As a result of the above measurem...

Page 51: ...n ring to get stuck in the groove and the condition will lead to reduce engine power output A piston whose sliding surface is badly grooved or seized due to overheating must be replaced Shallow grooves or minor scuff can be removed by grinding with emery paper of about 400 Piston pin bore Use a caliper gauge to measure the piston pin bore inside diameter if reading exceeds the following service li...

Page 52: ...cylinder bottom as shown in the illustration Service limit 0 75mm 0 0296 In As the piston ring wears its end gap increases reducing engine power output because of the resultant blow by through the enlarged gap Here lies the importance of using piston rings with end gaps with the limit Measure the piston ring free end gap to check the spring tension Service limit 3 6mm 0 142In Fix the piston ring i...

Page 53: ... Rev no 01 Page 58 of 143 Reed Valve Check the clearance A between reed valve and its seat and the dimension B If the clearance A is noted to exceed 0 2mm replace the reed valve assembly The dimension B is at least 1mm ...

Page 54: ...ocedure below Replace removed oil seals with new ones Apply special multipurpose grease to the lip of the oil seals Be sure to apply THREAD LOCK 1342 to outer surfaces of right and left crankshaft oil seals to prevent them from moving When fitting the oil seal into the crankcase insert it slowly with the special tools NOTE Align the oil seal with edge A of the crankcase as shown in the illustratio...

Page 55: ...1 Page 60 of 143 ENGINE MOUNTING BEARING PRESSING Using two steel tubes of appropriate size and a vise press the mounting bushings 1 and 2 into the crankcase holes as shown in the illustration Bushing crankcase Crankcase Bushing ...

Page 56: ...ES Rev no 01 Page 61 of 143 CRANK SHAFT Decide the length between the webs refer the figure at right when assembling the crankshaft Standard width between webs 38 0 1mm 1 496 0 004in When mounting the crankshaft into ...

Page 57: ...it is necessary to pull its left end into the crankcase with the special tool CAUTION Never fit the crankshaft into the the crankcase by driving it with a plastic hammer Always use the special tool otherwise crankshaft alignment accuracy will be affected ...

Page 58: ...s Install the two dowel pins Tighten the crankcase bolts securely with torque wrench at specified torque Torque 12 Nm 1 2 Kgm Check crankshaft rotation should be smooth Install the rear axle shaft 1 1into the crankcase by tapping its end lightly Apply engine oil on the left end of the rear axle shaft being inserted later in the reduction gear box cover Apply grease lightly on the rear brake cam pi...

Page 59: ...ft Aligning the tang on the wear indicator plate with a cutaway on the rear brake cam serrated end slide the indicator plate over the cam serration When installing the cam lever to the cam align the line on the cam with the slit of cam lever Tighten the cam lever nut to the specified torque Tightening Torque Wear indicator plate Cutaway Tang Line on the cam Slit ...

Page 60: ...VENTO MOTORCYCLES Rev 01 page91 of 143 6 8N m 0 6 0 8kgm Install the brake shoes Install the rear wheel ...

Page 61: ...the cir clip between its two faces one with sharp corners and the other with rounded corners When installing determine the direction of thrust being applied and position the cir clip so that it supports the thrust with it sharp corner securely pressing the shaft groove as shown in the illustration Thrust Sharp corner ...

Page 62: ...l washer new gasket and dowel pin Install the drive shaft to the gear case cover Install the retainer Tighten gearbox cover to the specified torque Tighten the oil drain bolt 11 Tightening Torque 10 12 N m 1 0 1 2Kgm Fill the gearbox with engine oil up to the oil level hole Oil Capacity 100ml SAE 85W 40 Starter pinion and starter gear Apply grease on the pinion shaft and install the starter pinion...

Page 63: ...pins bushing on the crankcase and install the starter idle gear cap Install the starter gear over the left crankshaft end Install the new O RING Install the starter motor When tightening the attachment screws secure the clamp together with the upper front screw ...

Page 64: ...VENTO MOTORCYCLES Rev 01 page95 of 143 MOVABLE DRIVEN AND CLUTCH ...

Page 65: ...VENTO MOTORCYCLES Rev 01 page96 of 143 Install the bearing in the fixed driven face with the special tools Install needle bearing ...

Page 66: ...ven face with the special tool Apply grease to the lip of oil seals and groove of inside of movable driven face NOTE When reinstalling the movable face to the fixed face make sure that the oil seal is positioned properly Install the pin at three places on the driven face hub Apply grease lightly to the cam part where the pins are placed Install two O Rings ...

Page 67: ... the movable driven face all the way outside to provide the maximum belt clearance CAUTION The belt should be positioned so that the arrows on the belt periphery points the normal turning direction The V belt contact face on the driven faces should be thoroughly cleaned to be free from oil Thoroughly clean the clutch housing to be free from oil and position it over the clutch shoe assembly Tighten...

Page 68: ...nd rolling surfaces for six roller weights For each weight approximately 1 5g of grease should be used Mount the three dampers 1 on the movable drive plate 2 and install it on the movable drive face Position the O RING on the movable drive face Install the movable drive face cover 3 NOTE ...

Page 69: ...e from oil Install the fixed drive fan Tighten the nut to the specified torque with special tool Tightening torque 50 60N M 5 0 6 0kg m Fill grease in the groove provided inside sliding surface of the kick driven gear and install on the end of the crankshaft Wipe off excess grease Install washer and spring NOTE When installing washer face the resin surface of washer to outside Install the retainer...

Page 70: ...43 driven faces will move together smoothly without slip Fill the final gearbox with engine oil up to the level hole Oil capacity 100 ml Tighten the oil level bolt to the specified torque Tightening torque 9 15N M 0 9 1 5 Kg m KICK STARTER ...

Page 71: ...ge102 of 143 Apply grease on inside surface of the kick starter shaft spacer Position the kick starter shaft return spring and hook the spring end on the clutch cover boss Install the dowel pins 1 Install the new gaskets 2 and 3 ...

Page 72: ...NTO MOTORCYCLES Rev 01 page103 of 143 Fix the gasket to the clutch cover as shown in the illustration NOTE Install the kick starter lever as shown in the illustration Tightening Torque 8 12N M 0 8 1 2kg m ...

Page 73: ... as to hug the locating pin as shown in illustration Apply CCI oil on the piston and install the piston to the connecting rod NOTE The arrow mark 1 on the piston head should point the exhaust side The cir clip should be mounted in such a position 2 that the mating ends of the cir clip do not coincide with the grove portion of the piston Position the cylinder base gasket Apply CCI oil on the positi...

Page 74: ...htening torque 18 28Nm 1 8 2 8 Kim OIL PUMP DRIVEN GEAR AND OIL PUMP Install right crankcase oil seal press board Apply grease to the oil pump driven gear and install into the crankcase Install the oil pump into the crankcase and tighten with specified torque Tightening Torque 3 5N m 0 3 0 5 kgm ...

Page 75: ...Rev 01 page106 of 143 Reed Valve Install reed valve paper gasket Install reed valve Install oil hose INTAKE PIPE Install the gasket and intake pipe with reed valve to the crankcase Install the clamps Install the oil hose ...

Page 76: ...on of the crankshaft and also the magneto rotor Install the key Install the stator and retainer and tighten with specified torque Apply thread lock super 1322 to the rotor nut and tighten it to the specified torque with the special tool Tightening torque 40 45N m 4 0 4 5kg m ...

Page 77: ...LES Rev 01 page108 of 143 Install the Rotor 1 and cooling fan 2 Install the magneto lead wire and starter motor lead wire correctly Install the cooling fan cover 3 Tighten the screw A and B Install fan guiding cover ...

Page 78: ... 01 page109 of 143 Install exhaust pipe screw 4 and screw 5 for tightening the muffler to their specified torque TIGHTENING ORQUE 4 8 12N m 0 8 1 2kg m 5 18 28N m 1 8 2 8kg m Lubricate brake cam shaft A with special grease ...

Page 79: ...VENTO MOTORCYCLES Rev 01 page110 of 143 CHAPTOR 4 FUEL AND LUBRICATION SYSTEM CONTENTS FUEL SWITCH CARBURETOR OIL PUMP ...

Page 80: ... on the fuel tap diaphragm through a passage way in the carburetor intake pipe and vacuum hose Due to this the negative pressure increases behind the fuel tap diaphragm until it is higher than this valves spring pressure The fuel valve in the fuel is then forced to open due to this diaphragm operation and allows fuel to flow into the carburetor float chamber Fuel switch ...

Page 81: ...or Type Identification code Throat tube diameter Main jet size Idle needle jet size Fuel needle clamp position Idle air adjusting screw Float height Throttle cable play Side Draught PZ19JB 19mm 80 57 5 3rd groove from top extrude 1 2 1 2 1 turnout 13 1mm 3 6 mm 0 1 0 2 In ...

Page 82: ...ct of fuel on engine and jet settings are made so as to satisfy and balance all of these conditions Therefore the jet should not be replaced with a size other than the original And the positions of adjustable parts should not be changed except when compensation for the mixture ratio due to altitude differences or other climatic conditions When adjustment is necessary refer to the following ...

Page 83: ... mixes with clean air in right proportion in the carburetor and then air fuel mixture is supplied to the combustion chamber of the engine In engine this air fuel mixture is controlled by the intake valve and camshaft rocker arm mechanism AIR FUEL FLOW CHART AIR FUEL Atmosphere Fuel tank Air cleaner assy Strainer fuel cock Filters Sedimentation bowl Fuel Tap Filter Venturi Inlet Floater Chamber Dif...

Page 84: ... Idling speed 10 12 1 Slow speed 12 14 1 Medium speed 15 17 1 High speed 13 15 1 CARBURETTOR CIRCUITS TRITON R4 CARBURETOR HAS FOLLOWING 6 MAIN CIRCUITS 1 Fuel Intake circuit 2 Choke circuit 3 Idling speed circuit 4 Slow speed circuit 5 Medium speed circuit 6 High speed circuit ...

Page 85: ...d for easy starting since it requires rich mixture Hence choke knob is being operated from the carburetor Due to this an air stopper Butterfly valve comes on the way to the venturi Air filter side of the carburetor thus reducing the amount of air being mixed with fuel Excessive fuel is being sucked from the slow jet and less quantity of air enters from the choke valve and from the small opening be...

Page 86: ...cceleration Air fuel mixture is being supplied by slow jet and also from main jet This is due to partial opening of throttle valve lifts needle jet upwards Hence some quantity of air fuel mixture coming out from main jet diffuser also mixes along with slow jet mixture to increase the mixture quantity as required by engine 5 MEDIUM SPEED CIRCUIT Economy speed range Further acceleration the air fuel...

Page 87: ...TION FROM MOTORCYCLE REMOVAL 1 Turn fuel switch OFF position 2 Disconnect fuel pipe from carburetor by pressing clip 3 Loosen the clamp over air cleaner connecting tube Air duct 4 Drain the fuel from carburetor float chamber in a separate pan loosening drains screw 5 Remove insulator clamp screw 6 Pull out the carburetor assy Along with insulator from air duct 7 Open the carburetor top cap pull ou...

Page 88: ...URE OF CARBURETTOR Screw the slow jet Ensure that all holes are clearly visible on the slow jet body Fix needle jet from main jet hole Ensure that the smaller dia face towards carburetor body hole Tighten the needle jet holder Ensure that all holes clearly visible on the needle jet holder body Screw the main jet along with jet holder Insert the float arm pin through the pivot and the float Check f...

Page 89: ...nticlockwise slowly till engine RPM increases to the peak highest speed position while setting Now stop adjusting air screw Maximum recommended air screw opening position 1 turns out 5 Readjust Idling speed to 1800 100 RPM by the throttle stop screw ensure that exhaust emission Carbon Monoxide CO 1 5 to 2 0 6 After adjusting Idling speed check for its stability flat spot missing if any by accelera...

Page 90: ... MOTORCYCLES Rev 01 page121 of 143 CHAPTER 5 ELECTRICAL SYSTEM CONTETNS IGNITION SYSTEM CHARGING AND LIGHTING SYSTEM STARTER SYSTEM FUEL GAUGE OIL LEVEL CHECK LIGHT AND TURN SIGNAL INDICATOR SWITCHS BARTTERY ...

Page 91: ...he ground to the gate of SCR 3 As the SCR conducts the energy which has been charged in the capacitor is instantaneously discharged through the primary winding of the ignition coil CDI UNIT AND IGNITION COIL INSPECTION CHECKING WITH ELECTRO TESTER Connect the CDI test lead to the coil s primary connector Connect the high tension leads red lead to the spark plug cord and the black lead to the black...

Page 92: ...p for at least five minutes continuously To insure proper operation under the temperature of actual riding MAGNETO EXCITING COIL Remove the right frame side cover Disconnect the exciting coil lead wire black with red tracer Using a Multimeter measure the resistance between the B R lead wire and ground If the resistance checked is incorrect replace the coil Exciting coil restance 140 220Ω Ω Ω Ω ...

Page 93: ...to stator and generate AC as the flywheel rotor turns AC generated in the charging coil flows to the regulator rectifier which changes AC to DC The DC Then charges the battery On the other hand lighting coil supplies AC current to the headlight taillight and meter light under the regulated condition R eg u la to r re ctifier F u se B atte r M a g n e t o H ead lig h t Ta illig h t L ig h t ...

Page 94: ...VENTO MOTORCYCLES ...

Page 95: ... the engine and keep it running at 5000 RPM with light switch turned on condition NOTE When making the test be sure that the battery is fully charged condition Digital Tachometer For measuring engine RPM Specified charging output Voltage 12 14 Volt at 5000 RPM Fuse Battery ...

Page 96: ...00 RPM STATOR COILS RESISTANCE VALUE Coil Description Resistance Value Charging Coil 285 to 375 Ω Pick up Coil 120 20 Ω at 20o C Light Coil Less than 2 Ω Battery Charging Coil Less than 2 Ω Use Multimeter tester to measure the resistance between the lead wire and ground If the checked resistance is incorrect replace the coil Regulator rectifier Disconnect the lead wire coupler Using the Multimeter...

Page 97: ...rter Motor Relay Starter switch and Battery Depressing the starter button while squeezing the front or rear brake lever energizes the relay causing the contact points to close which connects the starter motor to the battery Starter relay Starter motor Fuse Battery Starter button Front brake switch Ignition switch Rear brake switch ...

Page 98: ...motor will be unable to produce sufficient torque and the engine will be difficult to turn over To prevent the periodically inspect the length of the brushes and replace them when they are too short or chipping Service Limit 3 5mm 0 14in Commutator If the commutator surface is dirty starting performance will decrease Polish the commutator with 400 or similar fine emery paper when it is dirty Servi...

Page 99: ... armature STARTER RELAY INSPECTION Disconnect lead wire R W of the starter motor Turn on the ignition switch and squeeze the front or rear brake lever and then inspect the continuity between the Red and Red White lead wires at the starter relay when pushing the starter button If the starter relay is in sound condition continuity is found Disconnect the starter relay lead wire coupler Check the coi...

Page 100: ...he Y B and B W lead wires The fuel meter is normal if it s pointer indicates the E empty position when the specified voltage is applied to the circuit and if it s pointer indicates the F full position when the resistor is changed to 10 ohms If either one or both indications are abnormal replace the fuel gauge with a new one FUEL GAUGE SENDING UNIT INSPECTION Disconnect the lead wires coming out of...

Page 101: ...allen to a certain level the remaining amount of oil has become approximately 160 ml the oil level check light turns on and remains lit When the turn signal switch is turned on and the turn signal light flashes the turn signal indicator light oil level check light also flashes both being not concurrently but alternatively as one being lit white the other unit pl refer electric diagram below SWITCH...

Page 102: ...ATTERY SPECIFICATIONS Type designation YUASA YB4L B Capacity 12V 4Ah Specific gravity Fully charged Needs Charging 1 24 1 28 at 27 0 C Below 1 220 INITIAL CHARGING FILLNG ELECTROLYTE Remove the aluminum tape sealing the battery electrolyte filler holes ...

Page 103: ...ontainer Insert the nozzles of the electrolyte container into the battery s electrolyte filler holes holding the container firmly so that it does not fall Take precaution not to allow any of the fluid to spill Make sure air bubbles are coming up each electrolyte container and leave in the position for about more than 20 minutes NOTE If no air bubbles are coming up from a filter port tap the bottom...

Page 104: ...ls are found to be coated with rust or an acidic white powdery substance then this can be cleaned away with sandpaper RECHARGING OPERATION Apply multimeter to measure the voltage of battery If the reading is below 12 0V it should be recharge with a battery charger NOTE When recharging remove the battery form the vehicle NOTE When recharging don t remove the sealing caps from the battery Recharging...

Page 105: ...ON AND DISASSEMBLY REASSEMBLY AND REMOUNTING FRONT BRAKE BRAKE PAD REPLACEMENT CALIPER REMOVAL AND DISASSEMBLY CALIPER AND DISC INSPECTION CALIPER REASSEMBLY MASTER CYLINDER REMOVAL AND DISASSEMBLY MASTER CYLINDER INSPECTION MASTER CYLINDER REASSEMBLY AND REMOUNTING STEERING STEM AND FRONT SUSPENSION REMOVAL AND DISASSEMBLY INSPECTION REASSEMBLY AND REMOUNTING IGNITION SWITCH REAR WHEEL AND BRAKE ...

Page 106: ...t and helmet box by opening seat and by opening of 4 nos bolts 2 Open the screws 2 3 4 5 6 7 and remove decorating cap rear carrier 5 3 Unlock fuel tank cap and remove it open two tapping screws and then remove side cover 4 The sequence of assembly is the reverse of removal ...

Page 107: ...ews as sequence of illustration 2 Removing under cover by loosing the left and right tapping screws Under cover assembly 3 The assembly sequence is the reverse of disassembly Front cover removal 1 Unscrew tapping screw 1 and remove front cover 2 by removing front cover screw 3 ...

Page 108: ...NTO MOTORCYCLES Rev 01 page 138 of 143 LEGSHIELD REMOVAL 1 Remove power lock housing 2 and open bolt 1 3 Remove leg shield by opening the four bolts 3 4 The assembly sequence is the reverse of disassembly ...

Page 109: ...VENTO MOTORCYCLES Rev 01 page 139 of 143 HANDLE COVER REMOVAL a Remove front handle cover 2 by unscrewing the six Tapping screws 1 1 Remove master cylinder by removing the two bolts 3 ...

Page 110: ...VENTO MOTORCYCLES Rev 01 page 140 of 143 b Disconnect throttle cable 3 and oil pump cable 4 c Remove rear brake cable adjusting nut 5 ...

Page 111: ...VENTO MOTORCYCLES Rev 01 page 141 of 143 Handle cover removal 5 Remove all wiring couplers 6 Remove handle cover by unscrewing bolt 6 7 The assembly sequence is reverse of removal sequence ...

Page 112: ...Front wheel left bushing 10 Speedometer gear 11 valve cap Disassembly Remove the front brake caliper 2 by removing the two mounting bolts 1 3 NOTE Do not operate the front brake lever while dismounting the caliper Remove the left right decorating cover Remove front fender 6 Support the scooter on jack or wooden shelf Remove front wheel by removing front axle shaft ...

Page 113: ...he removed dust seal and bearing should be replaced with new ones AXLE SHAFT Check the axle shaft run out with a micrometer and replace it if the run out exceeds the limit Service limit 0 25mm 0 010in WHEEL RIM Make sure that the wheel rim run out does not exceed the service limit when checked as shown An excessive run out is usually due to worn or loose wheel bearings and can be reduced by replac...

Page 114: ...f removal and also carry out the following steps Install the wheel bearing with the special tools CAUTION Install the wheel bearing for left side Install the brake disc as shown in photo When installing this speedometer gear box align the two driving poles with the two reaxes of the wheel hub Tighten the nut with special tool ...

Page 115: ...brake lever while dismounting the calliper 1 Disc brake assy 2 Disc brake handle lever 3 Tightening bolt 4 Nut M6 5 Master cylinder 6 Tightening seat 7 Bolt M6X23 8 Brake hose assy 9 Brake caliper 10 Connecting board tightening bolt 11 Hose mounting bolt 12 Seal gasket 13 Front gasket 14 Gear gasket 15 Brake pad 1 16 Brake pad 2 17 Front brake switch 18 Brake disc ...

Page 116: ...ove the brake hose and collect the brake fluid in a suitable receptacle CAUTION Never re use the brake fluid left over from the last servicing And stored for long periods Remove the calliper Remove the brake pads Remove the spring and pad holder Place a rag over the piston to prevent popping up Froce out the piston with a air gun CAUTION Do not use high pressure air to prevent piston damage Remove...

Page 117: ...ubber parts for damage and wear Check the disc for wear with a micrometer Its thickness can be checked with disc and wheel in place Replace the disc if the Thickness exceeds the service limit Service Limit 3 5 mm 0 14 in With the disc mounted on the wheel check the disc face for runout with a dial gauge as shown Replace the disc if the run out exceeds the service limit Service Limit 0 3 mm 0 012 i...

Page 118: ...WARNING Bleed air after remounting the calliper refer to above pages MASTER CYLINDER REMOVAL AND DISASSEMBLY Remove the handlebar cover Refer to above page Disconnect the front brake light switch lead wires Place a cloth underneath the union bolt on the master cylinder to collect spilled drops of brake fluid Unscrew the union bolt and disconnect the brake hose master cylinder joint CAUTION Complet...

Page 119: ...move the piston primary cup with return spring Remove the reservoir cap and diaphragm Drain brake fluid MASTER CYLINDER INSPECTION Inspect the master cylinder bore for any scratches or other damage Check the piston surface for scratches or other damage Check the primary cup and dust boot for wear or damage ...

Page 120: ...UTION Wash the master cylinder components with fresh brake fluids before reassembly Never use cleaning solvent or gasoline to wash them Apply brake fluid to the cylinder bore and all the internals to be inserted into the bore Reassemble and remount the master cylinder When remounting the master cylinder on the handlebar first tighten the clamp bolt for upside CAUTION Bleed air after remounting the...

Page 121: ...rear brake cable 2 Remove throttle grip assy 3 Remove throttle cable 4 1 Handle jointing assy 2 Bolt GB5789 M10X1 25X45 3 Nut GB6187 M10X1 25 4 Left handlebar 5 Throttle grip assy 6 Screw GB818 M5X10 7 Sear brake cable assy 8 Throttle cable assy 9 Left switch comp 10 Right switch comp 11 Anti dust cover 12 Steel ball 5 13 Lower outer steel bowl 14 Connecting steel bowl 15 Under connecting board as...

Page 122: ...ing bolt Unscrew locknut with special tool Remove front fork assy by removing upper outer steel bowl NOTE Keep the steering stem balls safely Remove front fork Remove bearing lower race by special tool Remove steel balls Number of steel balls Upper 21 lower 21 Remove the upper and lower bearing inner races with an appropriate bar ...

Page 123: ...v 01 page 153 of 143 INSPECTION Check the removed parts for the following abnormalities Bearing race wear and brinelling Worn and damaged steel balls Distortion of steering stem or handlebar Check the suspension for damage ...

Page 124: ...ension arms Steel ball Apply grease when installing the upper and lower steel balls QTY upper 21 lower 21 Tighten the steering outer race with special tool and then extrude it 1 8 1 4round NOTE adjustment will vary from scooter to scooter Be sure that the steering turns smoothly and easily left to right Install a locknut by installing locknut and anti dust cover Screw locknut with special tool and...

Page 125: ... the specified torque Torque 37 44N M NOTE After performing the adjustment and installing the handlebar Rock the front wheel forward and backward to ensure that there is not play and that the procure is accomplished correctly If Play is noticeable readjust the steering outer race nut ...

Page 126: ...EAR WHEEL AND BRAKE 1 1 Tire 130 70 12 2 Rear rim assy 3 Brake pad kit assy 4 Brake pad kit spring 5 Rear brake tension 6 Rear indicator 7 Anti dust cover 8 Rear brake camshaft 9 Bolt M6Χ30 10 Valve 11 Nut M16Χ1 5 12 Rear brake arm 13 Valve cap ...

Page 127: ...locknut and rear wheel Remove brake shoes INSPECTION REAR RIM Measure inner diameter of rear rim hub with micrometer if measured diameter exceeds 110 7mm replace it with a new one Brake shoes Check the brake shoe and decide whether it should be replaced or not from the thickness of the brake shoe lining Service limit 2 5mm 0 09in ...

Page 128: ...e camshaft to the rear axle shaft side Install the protrusion 2 of indicator plate to the groove 3 Of Camshaft When installing the brake cam shaft align the groove 4 of camshaft with the slit 5 of on cam shaft When installing brake shoes be sure to daub camshaft with adequate grease CAUTION Be careful not to daub the camshaft with too much grease If grease gets on the lining brake effectiveness wi...

Page 129: ...O MOTORCYCLES Rev 01 page 159 of 143 SERVICING INFORAMTION Troubleshooting Battery Vehicle Wiring diagram Wire cable and brake hose routing Special tools Thread parts tightening torque Service data CONTENTS ...

Page 130: ...plug 2 Defective CDI ignition coil unit 3 Clogged fuel hose 4 Clogged jets in carburetor 5 Clogged exhaust pipe Clean Replace Clean Clean Clean Noisy engine Noise appears to come from piston 1 Piston or cylinder worn down 2 Combustion chamber fouled with carbon 3 Piston pin bearing or piston pin bore worn 4 Piston rings or ring grooves worn Noise seems to come from crankshaft 1 Worn or burnt crank...

Page 131: ...s in the movable drive face 12 Weakened movable driven face spring 13 Too rich fuel air mixture due to defective starter system Replace Replace Replace Adjust or replace Clean Adjust or replace Clean Clean or replace Retighten or replace Replace Replace Replace Replace Engine overheats 1 Heavy carbon deposit on piston crown 2 Defective oil pump or clogged oil circuit 3 Fuel level too low in float ...

Page 132: ...speed set too high 3 Incorrect gasoline 4 Dirty element in air cleaner 5 Spark plug loose 6 Incorrect engine oil Adjust carburetor Adjust carburetor Change Clean Replace by hot type plug Replace Spark plug electrodes overheat or burn 1 Spark plug too hot 2 The engine overheats 3 Spark plug loose 4 Mixture too lean 5 Not enough engine oil Replace by cold type plug Tune up Retighten Adjust carbureto...

Page 133: ...discharges too rapidly 1 Dirty container top and sides 2 Battery is too old Clean Replace CHASSIS Complaint Symptom and possible causes Remedy Handling feels too heavy 1 Steering stem nut over tightened 2 Broken bearing race in steering stem 3 Distorted steering stem 4 Not enough pressure in tires Adjust Replace Replace Adjust Wobbly handle 1 Loss of balance between right and left front suspension...

Page 134: ...n axle 5 Loose nuts on the rear shock 6 Worn engine mounting bushing 7 Loose nuts or bolts for engine mounting Replace Replace Replace Retighten Retighten Replace Tighten Front suspension too soft 1 Weakened springs 2 Oil leakage of shock absorber Replace Replace Front suspension too stiff 1 Not enough grease 2 Worn suspension arm spacer Refill Replace ...

Page 135: ... dirty with oil 8 Excessively worn drum 9 Too much brake lever play Repair or replace Replace Clean disc and pads Replace Bleed air Replace Replace Replace Adjust Brake squeaking 1 Carbon adhesion on pad surface 2 Tilted pad 3 Damaged wheel bearing 4 Worn pad 5 Foreign substance entered into brake fluid 6 Clogged return port of master cylinder 7 Brake shoe surface glazed 8 Loose front wheel axle o...

Page 136: ...VENTO MOTORCYCLES Rev 01 page 166 of 143 WIRE CABLE AND BRAKE HOSE ROUTING ...

Page 137: ...VENTO MOTORCYCLES Rev 01 page 167 of 143 ...

Page 138: ...VENTO MOTORCYCLES Rev 01 page 168 of 143 ...

Page 139: ...VENTO MOTORCYCLES Rev 01 page 169 of 143 Ignition coil Starting relay CDI HORN POWER SWITCH ...

Page 140: ...ON NO TOOL NUMBER DESCRIPTION 1 2 3 4 5 6 7 8 9 10 T01 T02 T03 T04 T05 T06 T07 T08 T10 T 11 T shape of sleeve Sleeve tools 7mm 8mm 10mm 12mm 13mm Flywheel remover Sleeve 18mm 24mm Screw remover Cylinder pressure gauge Piston pin remover Spark plug remover Flywheel lock bolt remover Clutch clamp 3 ...

Page 141: ...VENTO MOTORCYCLES Rev 01 page 171 of 143 10 ...

Page 142: ...ck screw 3 5 Oil pump lock screw 5 9 Right crankcase lock bolt 10 12 Bearing press board lock bolt 10 12 Cylinder double head bolt 15 18 Motor tightening bolt 10 12 Left crankcase cover lock screw 10 12 Left crankcase cover lock bolt 10 12 Main drive wheel face locknut 35 38 Driven wheel face locknut 35 38 Driven wheel face clutch locknut 55 60 Exceeding clutch outside lock screw 10 12 Electrical ...

Page 143: ...close end clearance 0 15 0 35 0 0059 0 0138 0 8 0 0315 1st ring 0 02 0 06 0 0008 0 0024 Piston ring to groove clearance 2en ring 0 02 0 06 0 0008 0 0024 Piston pin bore 10 002 10 008 0 3938 0 3940 10 030 0 3949 Piston pin outside diameter 9 994 10 000 0 3935 0 3937 9 98 0 3929 CONNECTING ROD CRANKSHAFT DESCRIPTION STANDARD LIMIT Conrod small end 13 995 14 006 0 5510 0 5514 14 040 0 5528 Conrod def...

Page 144: ...and type Side draft Identification code PZ19JB Venturi 19mm Main jet size 80 Pilot jet size 57 5 Needle position 3rd groove from top Idle air adjusting screw Open 1 2 1 2 1 turnout counter clock wise Float height 13 1mm ELECTRICAL DESCRIPTION SPECIFICATION NOTE Ignition timing 150 AT 1500RPM TYPE NGK R BR8HSA Spark plug GAP 0 6 0 8mm 0 020 0 028 Ignition coil resistance Primary secondary 0 2Ω 0 3Ω...

Page 145: ... φ110 mm φ110 7 mm Brake shoe thickness Rear 4mm 2 5 mm Brake disc thickness front 4 0 0 2 3 mm Tire size Front rear 120 70 12 130 70 12 Tire surface thickness front rear 120 130 SUSPENSION Front shock absorber stroke 88 mm Rear shock absorber stroke 45 mm Tire pressure Front tire air pressure 175kpa Rear tire air pressure 196kpa Fuel Engine oil Description Specification Remark Fuel type Unleaded ...

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