KYMCO VENOX 250 Service Manual
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KYMCO VENOX 250 Service Manual

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KYMCO
SERVICE MANUAL
VENOX 250
KYMCO
Overseas Sales Division
Overseas Service Department

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Summary of Contents for KYMCO VENOX 250

  • Page 1 KYMCO SERVICE MANUAL VENOX 250 KYMCO Overseas Sales Division Overseas Service Department...
  • Page 2 PREFACE This Service Manual describes the technical features and servicing procedures for the KYMCO VENOX 250. In this manual, many illustrations and drawings are used to help servicemen have better understanding. Section 2 contains the service precautions for all operations and troubleshooting stated in this manual.

  • Page 3: Table Of Contents

    TABLE OF CONTENTS GENERAL INFORMATION................. 1 INSPECTION/ADJUSTMENT..............2 LUBRICATION SYSTEM ................3 FUEL SYSTEM ....................4 ENGINE REMOVAL/INSTALLATION............5 CYLINDER HEAD/VALVES ................ 6 CRANKSHAFT/PISTON/CYLINDER............7 GENERATOR/LEFT CRANK CASE COVER ........... 8 CLUTCH/GEAR SHIFT MECHANISM............9 TRANSMISSION SYSTEM ................10 COOLING SYSTEM ..................11 FRONT WHEEL/SUSPENSION/STEERING ..........12 REAR WHEEL/BRAKE/SUSPENSION ............13 HYDRAULIC BRAKE ...................14...
  • Page 4 . GENERAL INFORMATION VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ GENERAL INFORMATION __________________________________________________________________________________ ENGINE SERIAL NUMBER/IDENTIFICATION......1- 1 SPECIFICATIONS ................1- 2 SERVICE PRECAUTIONS..............1- 3 SERVICE INFORMATION ..............1-10 TORQUE VALUES ................1-12 SPECIAL TOOLS ................1-14 LUBRICATION POINTS ..............1-16 WIRING DIAGRAM ................

  • Page 5: General Information

    . GENERAL INFORMATION VENOX ENGINE SERIAL NUMBER/IDENTIFICATION Location of Frame Serial Number Vehicle Identification Serial Number Location of Engine Serial Number...

  • Page 6: Specifications

    . GENERAL INFORMATION VENOX SPECIFICATIONS Air cleaner type Paper element Motorcycle name & Model No. VENOX 250 Fuel capacity 14 liter Chassis name & Model No. RA50AA Type Overall length (mm) 2325 Main Jet NO Front:112 Rear:108 Overall width (mm) φ30 equivalent...
  • Page 7 . GENERAL INFORMATION VENOX SERVICE PRECAUTIONS Make sure to install new gaskets, O-rings, circlips, cotter pins, etc. when reassembling. When tightening bolts or nuts, begin with larger-diameter to smaller ones at several times, and tighten to the specified torque diagonally. Use genuine parts and lubricants.
  • Page 8 . GENERAL INFORMATION VENOX Apply or add designated greases and lubricants to the specified lubrication points. After reassembly, check all parts for proper tightening and operation. When two persons work together, pay attention to the mutual working safety. Disconnect the battery negative (-) terminal before operation.
  • Page 9 . GENERAL INFORMATION VENOX If the fuse is burned out, find the cause and repair it. Replace it with a new one according to the specified capacity. Confirm Capacity After operation, terminal caps shall be installed securely. When taking out the connector, the lock on the connector shall be released before operation.
  • Page 10 . GENERAL INFORMATION VENOX The connector shall be inserted completely. If the double connector has a lock, lock it at the correct position. Snapping! Check if there is any loose wire. Check the double connector cover for proper coverage and installation. Before connecting a terminal, check for damaged terminal cover or loose negative terminal.
  • Page 11 . GENERAL INFORMATION VENOX After clamping, check each wire to make sure it is secure. Do not squeeze wires against the weld or its clamp. After clamping, check each harness to make sure that it is not interfering with any moving or sliding parts.
  • Page 12 . GENERAL INFORMATION VENOX Route harnesses so they are neither pulled tight nor have excessive slack. Do not pull too tight! Protect wires and harnesses with electrical tape or tube if they contact a sharp edge or corner. When rubber protecting cover is used to protect the wire harnesses, it shall be installed securely.
  • Page 13 . GENERAL INFORMATION VENOX After routing, check that the wire harnesses are not twisted or kinked. Wire harnesses routed along with handlebar should not be pulled tight, have excessive slack or interfere with adjacent or surrounding parts in all steering positions.
  • Page 14 . GENERAL INFORMATION VENOX Symbols: The following symbols represent the servicing methods and cautions included in this service manual. : Apply engine oil to the specified points. (Use the designated engine oil for lubrication.) Engine Oil : Apply grease for lubrication. : Caution Grease Special...
  • Page 15 . GENERAL INFORMATION VENOX SERVICE INFORMATION ENGINE Standard (mm) Service Limit (mm) Item Venox 250 Venox 250 ⎯ ⎯ Cylinder head warpage 57.975～57.99 57.81 Piston O.D.(10mm from bottom of piston skirt) 0.01～0.35 0.35 Cylinder-to- piston clearance 16.000～16.006 16.06 Piston pin hole I.D.
  • Page 16 . GENERAL INFORMATION VENOX FRAME Standard (mm) Service Limit (mm) Item Venox 250 Venox 250 Axle shaft runout 0.3/100mm Radial Front wheel rim runout Axial ⎯ ⎯ Front shock absorber spring free length Rear wheel rim runout Brake drum I.D.
  • Page 17 . GENERAL INFORMATION VENOX TORQUE VALUES ENGINE Item Thread dia. (mm) Torque (kg-m) Remarks Plate oil flowby M5×12 0.8～1.2 Connect rod nut M7×0.75 2.0～2.4 Oil drain M12×15 2.0～3.0 Plate ball brg holder 6×12 0.8～1.2 Drum gear shift 6×20 0.8～1.2 Shift fork comp 6×12 0.8～1.2 Sw assy neutral...
  • Page 18 . GENERAL INFORMATION VENOX FRAME Item Thread dia. Torque (kg-m) Remarks Strg stem nut 22×1.0 6.0～8.0 Thread comp strg head 26×1.0 0.15～2.5 or 1.2 Back 90° Top bridge 8×1.25 1.7～2.1 Bottom bridge 10×1.25 2.4～3.0 Front axle bolt 14×1.5 6.0～8.0 Rear axle nut 16×1.5 8.0～10.0 Front brake caliper...
  • Page 19 . GENERAL INFORMATION VENOX SPECIAL TOOLS Tool Name Tool No. Remarks Lock nut socket wrench E046 Lock nut wrench F006 12-11,12-12 Flywheel holder E021 8-3,8-4 Flywheel puller E042 Valve wrench 2-13 E036 Vacuum & CO adjuster E043 2-14 E045 2-14 Vacuum gauge Valve spring compressor E040...
  • Page 20 . GENERAL INFORMATION VENOX LUBRICATION POINTS ENGINE Lubrication Points Lubricant Remarks Crankcase sliding & movable parts SAE 5W-50 SF Cylinder movable parts SAE 5W-50 SF Drive chain SAE 80~90 Kick lever movable parts Grease Front suspension SAE 10W 400cc/piece Rear suspension SAE 5W 99cc/piece FRAME...
  • Page 21 . GENERAL INFORMATION VENOX WIRING DIAGRAM 1-17...
  • Page 22 . GENERAL INFORMATION VENOX CABLE & HARNESS ROUTING Clutch Cable Throttle Cable Wire Harness Front Brake Hose Speedometer Cable 1-18...
  • Page 23 . GENERAL INFORMATION VENOX Throttle Cable Ignition Coil Radiator 1-19...
  • Page 24 . GENERAL INFORMATION VENOX Battery Negative Terminal Battery Positive Terminal Choke Rod A.C.G Cord Air Cleaner Regulator/Rectifier Starter Relay Spark Plug Clutch Cable Rear Stop Switch 1-20...
  • Page 25 . GENERAL INFORMATION VENOX Fuse Battery Starter Relay Horn 1-21...

  • Page 26: Troubleshooting

    . GENERAL INFORMATION VENOX TROUBLESHOOTING ENGINE WILL NOT START OR IS HARD TO START Inspection/Adjustment Probable Cause Symptom Check if fuel reaches carburetor by loosening drain screw Empty fuel tank Clogged fuel line between fuel tank and carburetor Clogged float valve Clogged fuel filter Fuel does not Fuel reaches...
  • Page 27 . GENERAL INFORMATION VENOX ENGINE STOPS IMMEDIATELY AFTER IT STARTS Inspection/Adjustment Symptom Probable Cause Check if fuel reaches carburetor by loosening drain screw Empty fuel tank Fuel reaches Fuel does not Clogged float valve carburetor reach carburetor Clogged fuel filter Remove spark plug Plug not fouled or Plug fouled or...
  • Page 28 . GENERAL INFORMATION VENOX Symptom Inspection/Adjustment Probable Cause Check carburetor insulator rubber for air leaks. Carburetor not securely tightened No air leak Air leaks Faulty intake manifold gasket Deformed or broken carburetor O-ring 1-24...
  • Page 29 . GENERAL INFORMATION VENOX POOR PERFORMANCE (ENGINE LACKS POWER) Symptom Inspection/Adjustment Probable Cause Start engine and accelerate lightly for observation Clogged air cleaner Poor fuel flow (Restricted) Engine speed Engine speed does not Clogged fuel tank cap breather hole increases increase sufficiently Clogged exhaust muffler Carburetor fuel level too low...
  • Page 30 . GENERAL INFORMATION VENOX POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS) Inspection/Adjustment Symptom Probable Cause Check ignition timing Faulty CDI unit Correct Incorrect Faulty A.C. generator Check carburetor pilot screw adjustment Mixture too lean (turn screw in) Correctly adjusted Incorrectly adjusted Mixture too rich (turn screw out)
  • Page 31 . GENERAL INFORMATION VENOX POOR PERFORMANCE (AT HIGH SPEED) Inspection/Adjustment Symptom Probable Cause Check ignition timing Faulty CDI unit Correct Incorrect Loose A.C. generator stator Faulty A.C. generator Check valve clearance Improperly adjusted valve clearance Correct Incorrect Worn valve seat Check fuel tank for fuel supply Empty fuel tank...
  • Page 32 . GENERAL INFORMATION VENOX STARTER MOTOR 1. Starter motor won‘t turn Symptom Inspection/Adjustment Probable Cause Check operation of stop switch by applying brake Burned out fuse Weak or dead battery Stoplight does not Stoplight comes on Faulty stop switch come on Loose or disconnected connector Check battery circuit Broken or shorted ignition...
  • Page 33 . GENERAL INFORMATION VENOX STEERING HANDLEBAR DOES NOT TRACK STRAIGHT Symptom Probable Cause (Front and rear tire pressures are normal) Steering stem nut too tight Steering is heavy Broken steering steel balls Excessive wheel bearing play Front or rear wheel is Bent rim wobbling Loose axle nut...
  • Page 34 . GENERAL INFORMATION VENOX POOR SUSPENSION PERFORMANCE Symptom Probable Cause (Front and rear tire pressures are normal) Weak shock spring Suspension is too soft Excessive load Shock damper oil leaking Bent fork tube or damper rod Suspension is too hard Fork slider and tube binding Fork tube and spring binding Suspension is noisy...
  • Page 35 . GENERAL INFORMATION VENOX FUEL GAUGE 1. Pointer does not register correctly (Ignition switch ON) Inspection/Adjustment Symptom Probable Cause Check battery circuit by operating turn signals Burned out fuse Weak or dead battery Signals operate Signals dim, remain Faulty ignition switch properly on or don‘t operate Loose or disconnected connector...
  • Page 36 . GENERAL INFORMATION VENOX POOR CHARGING (BATTERY OVER DISCHARGING OR OVERCHARGING) Undercharging Inspection/Adjustment Symptom Probable Cause Start engine and test limit voltage between battery terminals Dead battery Voltage does not Normal voltage increase Faulty battery Measure resistance between AC generator coil terminals Faulty coil Normal...
  • Page 37 . GENERAL INFORMATION VENOX NO SPARK AT SPARK PLUG Inspection/Adjustment Symptom Probable Cause Replace with a new spark plug and inspect again Weak or no spark Good spark Faulty old spark plug Check spark plug cap and ignition coil wire for loose connection Not loose Loose...
  • Page 38 . INSPECTION/ADJUSTMENT VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ INSPECTION/ADJUSTMENT __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 2- 1 MAINTENANCE SCHEDULE-------------------------------------------- 2- 2 BRAKE SYSTEM ----------------------------------------------------------- 2- 3 BRAKE SHOE --------------------------------------------------------------- 2- 4 WHEELS/TIRES ------------------------------------------------------------ 2- 4 SUSPENSION---------------------------------------------------------------- 2- 5 CLUTCH---------------------------------------------------------------------- 2- 6 DRIVE CHAIN -------------------------------------------------------------- 2- 7 SPARK PLUG---------------------------------------------------------------- 2- 7 IGNITION TIMING--------------------------------------------------------- 2- 8 THROTTLE OPERATION------------------------------------------------- 2- 8...

  • Page 39: Service Information

    . INSPECTION/ADJUSTMENT VENOX SERVICE INFORMATION GENERAL WARNING •Before running the engine, make sure that the working area is well-ventilated. Never run the engine in a closed area. The exhaust contains poisonous carbon monoxide gas which may cause death to people. •Gasoline is extremely flammable and is explosive under some conditions.

  • Page 40: Maintenance Schedule

    . INSPECTION/ADJUSTMENT VENOX MAINTENANCE SCHEDULE In order to have a safe riding, maintain good performance, prolong the motorcycle service life and reduce pollution, make sure to perform the periodic inspection and maintenance. I: Inspect and clean, lubricate, refill, repair or replace if necessary. A: Adjust C: Clean R: Replace T: Tighten Regular Service Mileage (km) Whichever...
  • Page 41 . INSPECTION/ADJUSTMENT VENOX BRAKE SYSTEM BRAKE LEVER & PEDAL Free Play Measure the rear brake pedal free plays. Free Play: Rear: 20～30mm Adjusting Nut If the free plays do not fall within the limits, adjust by turning the adjusting nuts. Adjusting Nut If the pedal height is unsuitable, turning the adjusting nut.
  • Page 42 Check the tire pressure. Tire pressure should be checked when the tires are cold. TIRE PRESSURE 1 Rider 2 Riders Front 2.0 kg/cm² 2.0 kg/cm² Rear 2.0 kg/cm² 2.25 kg/cm² TIRE SIZE Model VENOX 250 Item Front 120/80–17 Rear 150/80-15...
  • Page 43 . INSPECTION/ADJUSTMENT VENOX Bolts Check the front and rear axle nuts for looseness. If the axle nuts are loose, tighten them to their specified torques. Torques: Front : 6.0～8.0kg-m Rear : 8.0～10.0kg-m Axie Nut “T” Mark SUSPENSION FRONT Fully apply the front brake lever and check the action of the front shock absorbers by compressing them several times.

  • Page 44: Steering Handlebar

    . INSPECTION/ADJUSTMENT VENOX STEERING HANDLEBAR Check that the control cables do not interfere with handlebar rotation. Raise the front wheel off the ground and check that the steering handlebar rotates freely. If the handlebar moves unevenly, binds, or has vertical movement, adjust the steering head bearing.

  • Page 45: Drive Chain

    . INSPECTION/ADJUSTMENT VENOX DRIVE CHAIN Check the drive chain slack. Specified Slack: 10～20mm Drive Chain Adjustment: Rear Axle Nut 1. First loosen the rear axle nut. 2. Adjust the right and left chain adjusting nuts to align the right and left index marks with the punch marks on the chain adjusters.
  • Page 46 . INSPECTION/ADJUSTMENT VENOX IGNITION TIMING The CDI ignition timing is not adjustable, a kind of fully transistor ignition. If the timing is incorrect, check the CDI unit, ignition coil and A.C. generator and replace any faulty parts. Remove the ignition timing eye hole cap on the left crankcase cover.
  • Page 47 . INSPECTION/ADJUSTMENT VENOX Lock Nut Adjusting Nut When minor adjustment is required, adjust by turning the adjusting nut on the throttle cable. Choke Rod Check the choke rod operating properly if smoothly or not. Choke Rod Valve Remove the choke rod valve. Check the choke rod valve for wear, fouling and carbon deposits.
  • Page 48 . INSPECTION/ADJUSTMENT VENOX If the oil level is low, add the recommended oil to the proper level. Recommended Oil: SAE 5W-50 API:SF When changing engine oil, be sure to tighten Drain Bolt the drain bolt securely. Check the drain bolt washer for damage. Oil Capacity: Full capacity : 2.5 liter At change with oil filter : 2.2 liter At change without oil filter : 2.0 liter...
  • Page 49 . INSPECTION/ADJUSTMENT VENOX Upper Limit COOLING SYSTEM Place the motorcycle on its main stand on level ground for coolant level check. Check if the coolant level is between the upper and lower limits on the reserve tank. If the coolant level is too low, it means that there are abnormal conditions.
  • Page 50 . INSPECTION/ADJUSTMENT VENOX Screws AIR CLEANER AIR CLEANER REPLACEMENT Remove the right side cover. Remove the air cleaner case cover screws and the cover. Remove the air cleaner element. Check the element and replace it with a new one if it is excessively dirty or damaged. CHANGE INTERVAL Air Cleaner More frequent replacement is required if...
  • Page 51 . INSPECTION/ADJUSTMENT VENOX Bolts VALVE CLEARANCE Inspect and adjust valve clearance while the engine is cold (below 35 ). Remove the four cylinder head cover bolts and the cylinder head cover. Front cylinder: Rotate the generator flywheel to bring the camshaft to the top dead center on the compression stroke and align the “T1”...
  • Page 52 . INSPECTION/ADJUSTMENT VENOX 9.Adjust the CO density of the front/rear carburetor at 3.0±0.5% by turning the pilot screw. 10.Slightly turn the throttle grip for several time again and recheck if the idle speed, vacuum value and CO density is within the specified range.
  • Page 53 . LUBRICATION SYSTEM VENOX LUBRICATION SYSTEM...

  • Page 54: Lubrication System

    . LUBRICATION SYSTEM VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ LUBRICATION SYSTEM __________________________________________________________________________________ SERVICE INFORMATION ..............3-2 TROUBLESHOOTING ............... 3-2 ENGINE OIL/OIL FILTER ..............3-3 OIL PUMP.................... 3-4...
  • Page 55 . LUBRICATION SYSTEM VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • The service and maintenance of this section can be accomplished with the engine installed in the frame. • Use care when removing and installing the oil pump not to allow dust and foreign matters to enter the engine and oil line.
  • Page 56 . LUBRICATION SYSTEM VENOX Upper Limit ENGINE OIL/OIL FILTER OIL LEVEL • Place the motorcycle upright on level ground for engine oil level check. • Run the engine for 2～3 minutes and check the oil level after the engine is stopped for 2～3 minutes.

  • Page 57: Oil Pump

    . LUBRICATION SYSTEM VENOX Clutch Cable OIL PUMP REMOVAL 1. Disconnect the clutch cable. 2. Remove the right crankcase cover bolts and right crankcase cover. When installing, make sure to use a new right crankcase cover gasket. Right Crankcase Cover Bolts Remove the bolt attaching the starter gear.
  • Page 58 . LUBRICATION SYSTEM VENOX Bolts DISASSEMBLY Remove the three oil pump mounting bolts and the oil pump body. Outer Rotor Feeler Gauge INSPECTION Measure the pump body-to-outer rotor clearance. Service Limit: 0.20mm Pump Body Outer Rotor Feeler Gauge Measure the inner rotor-to-outer rotor clearance.
  • Page 59 . LUBRICATION SYSTEM VENOX Outer Rotor Pump Shaft ASSEMBLY Install the outer rotor and inner rotor into the pump body. Insert the pump shaft. Insert the pump shaft by aligning the flat on the shaft with the flat in the inner rotor.
  • Page 60 . FUEL SYSTEM VENOX...
  • Page 61 . FUEL SYSTEM VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ FUEL SYSTEM __________________________________________________________________________________ SERVICE INFORMATION ..............4- 2 TROUBLESHOOTING ............... 4- 3 CARBURETOR REMOVAL .............. 4- 4 VACUUM CHAMBER................ 4- 5 AIR CUT-OFF VALVE ............... 4- 6 FLOAT CHAMBER ................4- 6 AUTO FUEL VALVE .................

  • Page 62: Fuel System

    . FUEL SYSTEM VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS Gasoline is very dangerous. When working with gasoline, keep sparks and flames away from the working area. Gasoline is extremely flammable and is explosive under certain conditions. Be sure to work in a well-ventilated area. •...
  • Page 63 . FUEL SYSTEM VENOX TROUBLESHOOTING Engine cranks but won’t start Engine lacks power • No fuel in tank • Clogged air cleaner • No fuel to carburetor • Faulty carburetor • Cylinder flooded with fuel • Faulty ignition system • No spark at plug •...

  • Page 64: Carburetor Removal

    . FUEL SYSTEM VENOX Screw CARBURETOR REMOVAL Remove the seat and fuel tank. Loosen the air cleaner connecting tube band screw. Bolt Remove the five lock bolts. Remove the carburetor cap. Air Cleaner Adjusting Nut Lock Nut Loosen the throttle cable adjusting nut and lock nut, and disconnect the throttle cable from the carburetor.
  • Page 65 . FUEL SYSTEM VENOX Screw VACUUM CHAMBER DISASSEMBLY Remove the four vacuum chamber cover screws and the cover. Vacuum Chamber Cover Spring Remove the spring , vacuum diaphragm and piston. Vacuum Diaphragm Remove the needle holder and jet needle. Be careful not to damage the vacuum diaphragm.
  • Page 66 . FUEL SYSTEM VENOX ASSEMBLY Install the vacuum piston/diaphragm in the carburetor body. Install the spring and then install the vacuum chamber cover. Tighten the four screws. • Be careful not to damage the diaphragm. • Hold the vacuum piston while tightening the vacuum chamber cover.
  • Page 67 . FUEL SYSTEM VENOX Slow Jet Pilot Screw Needle Jet Remove the main jet, needle jet holder, needle jet, slow jet and pilot screw. • Be careful not to damage the fuel jets and pilot screw. • Before removing, turn the pilot screw in and carefully count the number of turns until it seats lightly and then make a note of this.
  • Page 68 . FUEL SYSTEM VENOX Float Install the float valve, float and float pin. Secure the float pin with the screw. Float Pin Screw FLOAT LEVEL INSPECTION Float Level Gauge • Check the operation of the float valve and float before this inspection. •...
  • Page 69 . FUEL SYSTEM VENOX INSTALLATION Install the fuel tank in the reverse order of removal. AIR CLEANER Bolt Loosen the air cleaner connecting tube band screw. Disconnect the transmission case breather tube from the air cleaner. Remove the bolt and air cleaner case. The installation sequence is the reverse of removal.
  • Page 70 . ENGINE REMOVAL/INSTALLATION VENOX 3.5~4.5kg-m 2.4~3.0kg-m 0.8~1.2kg-m 3.5~4.5kg-m...
  • Page 71 5. ENGINE REMOVAL/INSTALLATION VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ ENGINE REMOVAL/INSTALLATION __________________________________________________________________________________ SERVICE INFORMATION ..............5- 2 ENGINE REMOVAL ................5- 3 ENGINE INSTALLATION ..............5- 6...
  • Page 72 . ENGINE REMOVAL/INSTALLATION VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • A engine stand or floor jack is required to support and maneuver the engine. • The following parts can be serviced with the engine installed in the frame: ⎯ Cylinder head/valves (Section 6) ⎯...

  • Page 73: Engine Removal

    5. ENGINE REMOVAL/INSTALLATION VENOX Fuel Tank ENGINE REMOVAL Remove the seat and fuel tank. Remove the left and right side cover. Disconnect the fuel tube from the auto fuel valve. Disconnect the speedometer wire coupler from the hardness wire. Generator Wire Coupler Disconnect the A.C.
  • Page 74 . ENGINE REMOVAL/INSTALLATION VENOX Remove the exhaust muffler brace lock bolt. Torgue: 3.0~3.6kg-m Bolt Bolt Remove the exhaust muffler hanger lock bolt. Remove the exhaust muffler. Torgue: 3.0~3.6kg-m Clutch Cable Disconnect the clutch cable. Remove the coolant hose. Hose...
  • Page 75 5. ENGINE REMOVAL/INSTALLATION VENOX Left Rear Remove the gear shift pedal attaching bolt Crankcase Cover and the gear shift pedal. Remove the three left rear crankcase cover attaching bolts and the cover. Gear Shift Pedal Drive Chain Remove the drive gear attaching bolt. Remove the drive gear and drive chain.

  • Page 76: Engine Installation

    . ENGINE REMOVAL/INSTALLATION VENOX Lower Bracket Nut Remove the lower bracket bolt and nut. Tilt the engine to dismount the engine from right side. Torgue: 3.5~4.5kg-m ENGINE INSTALLATION Install the engine in the reverse order of removal. Install the engine to its original position with a jack or other adjustable support.
  • Page 77 . CYLINDER HEAD/VALVES VENOX 1.0~1.4kg-m 1.0~1.4kg-m...
  • Page 78 6. CYLINDER HEAD/VALVES VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ CYLINDER HEAD/VALVES __________________________________________________________________________________ SERVICE INFORMATION ..............6- 2 TROUBLESHOOTING ............... 6- 3 CYLINDER HEAD BOLTS TORQUE TABLE ......... 6- 4 CYLINDER HEAD COVER REMOVAL .......... 6- 5 ROCKER ARMS DISASSEMBLY............. 6- 7 CYLINDER HEAD ASSEMBLY ............
  • Page 79 . CYLINDER HEAD/VALVES VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • When assembling, apply engine oil to the valve guide movable parts, valve arm and camshaft sliding surfaces for initial lubrication. • The valve rocker arm is lubricated with engine oil through the cylinder head engine oil passages. Clean and unclog the oil passages before cylinder head assembly.
  • Page 80 6. CYLINDER HEAD/VALVES VENOX TROUBLESHOOTING • The poor cylinder head operation can be diagnosed by a compression test or by tracing engine top-end noises. Poor performance at idle speed White smoke from exhaust muffler • Compression too low • Worn or broken valve stem or valve guide •...
  • Page 81 . CYLINDER HEAD/VALVES VENOX CYLINDER HEAD BOLTS TORQUE TORQUE TABLE BF 8*71 BF 8*151 washer BF 8*48 BF 8*131 BF 8*131 Sequence Torque kgf-m Tightening Tightening Tightening Tightening...

  • Page 82: Cylinder Head Cover Removal

    6. CYLINDER HEAD/VALVES VENOX Bolts CYLINDER HEAD COVER REMOVAL Remove the eight cylinder head cover bolts for twin cylinder cover. Remove the cylinder head cover. Inspect the cylinder head cover O-ring for damage or deterioration and replace if necessary. Torgue: 0.8~1.2kg-m Remove the cam chain tensioner cap screw and the O-ring.
  • Page 83 . CYLINDER HEAD/VALVES VENOX Dowel Pins Remove the camshaft holder and dowel pins. Remove the camshaft gear from the cam Cam Chain chain and remove the camshaft. Suspend the cam chain with a piece of wire to keep it from falling into the crankcase.
  • Page 84 6. CYLINDER HEAD/VALVES VENOX Bolt CYLINDER HEAD REMOVAL Remove the cylinder head bolt. Remove the cylinder head. ROCKER ARMS DISASSEMBLY Rocker Arm Remove the rocker arm shafts. Remove the rocker arm. Rocker Arm Shafts Washer Check the rocker arm shafts washer and O- ring for damage or deformation and replace with a new one if necessary.
  • Page 85 . CYLINDER HEAD/VALVES VENOX Measure the diameter of this column. Service Limits: 9.94mm replace if below CYLINDER HEAD DISASSEMBLY Remove the valve spring cotters, retainers, springs, spring seats, washers and valve stem seals with a valve spring compressor. • Be sure to compress the valve springs with a valve spring compressor.
  • Page 86 6. CYLINDER HEAD/VALVES VENOX VALVE /VALVE GUIDE Inspect each valve for bending, burning, scratches or abnormal stem wear. Check valve movement in the guide. Measure each valve stem O.D. Service Limits: 4.90mm replace if below 4.90mm replace if below Measure each valve guide I.D. Valve Guide Service Limits: IN: 5.05mm replace if over EX: 5.05mm replace if over...
  • Page 87 . CYLINDER HEAD/VALVES VENOX Plastic Hammer Tap the valve stems gently with a plastic hammer for 2～3 times to firmly seat the cotters. Be careful not to damage the valves. ROCKER ARMS INSTALLATION Install the rocker arm shafts bolt and the rocker arm.
  • Page 88 . CRANKSHAFT/PISTON/CYLINDER VENOX 2.4kg-m 2.4kg-m...
  • Page 89 . CRANKSHAFT/PISTON/CYLINDER VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ CRANKSHAFT/PISTON/CYLINDER __________________________________________________________________________________ SERVICE INFORMATION ..............7- 1 TROUBLESHOOTING ............... 7- 1 CRANKCASE REMOVAL ..............7- 3 CRANKSHAFT REMOVAL............... 7- 4 PISTON REMOVAL ................7- 5 PISTON INSTALLATION ..............7- 6 CYLINDER INSPECTION..............7- 7 CONNECTING ROD BEARING CHOICE ........

  • Page 90: Specifications

    • Both of crankcase need to be replaced if anyone crankcase is damaged. • After disassembly, clean the removed parts and dry them with compressed air before inspection. SPECIFICATIONS Standard (mm) Service Limit (mm) Item VENOX 250 VENOX 250 I.D. 58.0～58.015 58.30 ⎯...
  • Page 91 . CRANKSHAFT/PISTON/CYLINDER VENOX Bolts CRANKCASE REMOVAL The following parts must be removed before removing the crankcase: • Cylinder head /camshaft. • Starter motor/generator/left and right crankcase cover/clutch. • Clutch/gear shift mechanism. Remove the six attaching bolts on the upper crankcase. Bolts Remove the eleven attaching bolts on the lower crankcase.
  • Page 92 . CRANKSHAFT/PISTON/CYLINDER VENOX Nuts CRANKSHAFT REMOVAL Remove the four attaching nut on the connecting rod cap. Remove the connecting rod cap. Torgue: 2.4kg-m Crankshaft Remove the crankshaft. INSPECTION Measure the crankshaft runout. Service Limit: 0.1mm replace if over...
  • Page 93 . CRANKSHAFT/PISTON/CYLINDER VENOX Piston/Connecting Rod PISTON REMOVAL Remove the piston/connecting rod. Piston Piston Pin Remove the piston pin clip. Take out the piston pin. Clip INSPECTION Inspect the piston, piston pin and piston rings. Remove the piston rings. Take care not to damage or break the piston rings during removal.
  • Page 94 . CRANKSHAFT/PISTON/CYLINDER VENOX Insert each piston ring into the cylinder bottom. Use the piston head to push each piston ring into the cylinder. Measure the piston ring end gap. Service Limit: 0.50mm Measure the piston pin hole I.D. Service Limit: 16.012mm replace if over Measure the piston pin O.D.
  • Page 95 . CRANKSHAFT/PISTON/CYLINDER VENOX CYLINDER INSPECTION Inspect the cylinder bore for wear, scratches or damage. Measure the cylinder I.D. at three levels of top, middle and bottom at 90° to the piston pin (in both X and Y directions). Service Limit: 58.30mm replace if over Measure the cylinder-to-piston clearance and take the maximum figure measured.
  • Page 96 . CRANKSHAFT/PISTON/CYLINDER VENOX Crank Pin Mark There is a mark on the connecting rod big end. Connecting Rod Crank Pin Bearing Big End Mark Mark Chose(Color) A(Brown) B(Green) B(Green) C(Yellow) First install the plate bearings before the connecting rod big end is installed. Press the flange on the plate bearing into the connecting rod groove.
  • Page 97 . CRANKSHAFT/PISTON/CYLINDER VENOX A.C.G. Side Mark CRANK BEARING CHOICE Crankcase Crank Pin Bearing Mark Mark Chose(Color) A(Brown) B(Green) B(Green) C(Yellow) One-Way Side Mark Flange First install the plate bearings before installing the upper and lower crankcase. Apply engine oil to the plate bearing on the crankcase.
  • Page 98 . CRANKSHAFT/PISTON/CYLINDER VENOX Piston INSTALLATION Install other removed parts in the reverse of order of removal. 7-10...
  • Page 99 8. GENERATOR/LEFT CRANK CASE COVER VENOX 7.5~8.5kg-m 0.8~1.2kg-m...

  • Page 100: Generator/Left Crank Case Cover

    8. GENERATOR/LEFT CRANK CASE COVER VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ GENERATOR/LEFT CRANK CASE COVER __________________________________________________________________________________ SERVICE INFORMATION ..............8-2 TROUBLESHOOTING ............... 8-2 LEFT CRANKCASE COVER/GENERATOR REMOVAL....8-3 GENERATOR INSTALLATION............8-4...
  • Page 101 8. GENERATOR/LEFT CRANK CASE COVER VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • The starter motor, generator, left crankcase cover and starter clutch can be serviced in the frame. • Do not install the starter clutch forcedly. • Install the generator by aligning the groove in the flywheel with the key on the crankshaft. TORQUE VALUE Flywheel nut: 7.5～8.5kg-m SPECIAL TOOLS...
  • Page 102 8. GENERATOR/LEFT CRANK CASE COVER VENOX Generator Wire Coupler LEFT CRANKCASE COVER/ GENERATOR REMOVAL Remove the seat and fuel tank. Remove the left and right side cover. Disconnect the fuel tube from the auto fuel valve. Disconnect the A.C. generator and starter motor wire coupler.
  • Page 103 8. GENERATOR/LEFT CRANK CASE COVER VENOX Flywheel Puller Install the flywheel puller. Flywheel Remove the flywheel using a flywheel puller. GENERATOR INSTALLATION Groove Install the generator flywheel. Hold the flywheel with a flywheel holder and tighten the flywheel lock bolt. •...
  • Page 104 . CLUTCH/GEAR SHIFT MECHANISM VENOX 1.8~2.5kg-m 7.5~8.5kg-m 5.5~6.5kg-m 0.8~1.2kg-m...

  • Page 105: Clutch/Gear Shift Mechanism

    . CLUTCH/GEAR SHIFT MECHANISM VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ CLUTCH/GEAR SHIFT MECHANISM __________________________________________________________________________________ SERVICE INFORMATION ..............9-2 TROUBLESHOOTING ............... 9-3 RIGHT CRANKCASE COVER REMOVAL ........9-4 ONE WAY CLUTCH REMOVAL............9-4 CLUTCH REMOVAL ................. 9-6...
  • Page 106 . CLUTCH/GEAR SHIFT MECHANISM VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • The clutch and gear shift mechanism can be serviced in the frame. • Install the clutch plates in the same chamfer direction. • Install the thrust washer with the chamfer facing up and the flat facing down. SPECIFICATIONS Item Standard (mm)
  • Page 107 . CLUTCH/GEAR SHIFT MECHANISM VENOX TROUBLESHOOTING Clutch slips during acceleration Clutch won’t operate and motorcycle • No free play moves slowly • Worn friction disk • Excessive free play • Weak spring • Bent clutch plate Clutch won’t operate Too much pressure on clutch lever •...
  • Page 108 . CLUTCH/GEAR SHIFT MECHANISM VENOX Right Crankcase Cover RIGHT CRANKCASE COVER REMOVAL Drain the engine oil. Disconnect the clutch cable. Remove the right crankcase cover attaching bolts and right crankcase cover. Bolts Remove the right crankcase cover. Bolt ONE-WAY CLUTCH REMOVAL Remove the one-way clutch mounting bolt and one-way clutch.
  • Page 109 . CLUTCH/GEAR SHIFT MECHANISM VENOX Measure the starter gear shaft O.D. and I.D. Service Limit: O.D. 42.0mm replace if over. I.D. 32.20mm replace if below. One-Way Clutch Remove the one-way clutch rollers, plungers and springs. Bearing Check the one-way clutch bearing for smooth turning.
  • Page 110 . CLUTCH/GEAR SHIFT MECHANISM VENOX INSTALLATION Install the one-way clutch and starter reduction gear in the reverse order of removal. Align the flange of the one-way clutch with the crank mark. CLUTCH REMOVAL Clutch Lifter Tension Springs Remove the four clutch lifter bolts. Remove the clutch lifter and four tension springs.
  • Page 111 . CLUTCH/GEAR SHIFT MECHANISM VENOX Clutch Center Remove the clutch center, clutch friction disks and plates. Remove the washer, clutch outer. Washer Clutch Outer INSPECTION CLUTCH TENSION SPRING Measure each clutch tension spring free length. Service Limit: 31.0mm replace if below CLUTCH FRICTION DISK Clutch Friction Disk Measure each clutch friction disk thickness.
  • Page 112 . CLUTCH/GEAR SHIFT MECHANISM VENOX CLUTCH PLATE Measure each clutch plate bending using a feeler gauge. Service Limit: 0.10mm replace if over Feeler Gauge Clutch Plate Clutch Outer CLUTCH OUTER Inspect the clutch outer groove for scratches caused by the friction disks. Measure the clutch outer I.D.
  • Page 113 .TRANSMISSION SYSTEM VENOX 10-0...
  • Page 114 .TRANSMISSION SYSTEM VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ TRANSMISSION SYSTEM __________________________________________________________________________________ SERVICE INFORMATION ..............10- 2 TROUBLESHOOTING ............... 10- 3 GEAR SHIFT MECHANISM REMOVAL......... 10- 4 CRANKCASE REMOVAL ..............10- 5 10-1...
  • Page 115 .TRANSMISSION SYSTEM VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • During crankcase separation, do not separate the crankcase halves with an iron hammer to avoid crankcase deformation or damage. • After separation, be careful not to damage the right and left crankcase mating surfaces to avoid oil leakage.
  • Page 116 .TRANSMISSION SYSTEM VENOX TROUBLESHOOTING Excessive engine noise • Worn main shaft journal bearing • Worn crankshaft pin bearing • Worn transmission bearings Transmission gear tripping • Worn gear teeth • Bent transmission fork • Bent transmission fork shaft • Damaged gear shift cam stopper Hard shifting •...
  • Page 117 .TRANSMISSION SYSTEM VENOX Bolts GEAR SHIFT MECHANISM REMOVE Remove the gear shift pedal. Remove the two water pump attaching bolts and remove the water pump. Water Pump Remove the three gear shift mechanism Bolts cover attaching bolts. Remove the gear shift mechanism cover. Cover Remove the gear shift spindle.
  • Page 118 .TRANSMISSION SYSTEM VENOX Gear Shift Cam Remove the stopper and spring attaching bolts. Remove the gear shift cam bolt. Remove the gear shift cam and set pin. Stopper Spring GEAR/SHAFT COLLAR INSPECTION Ball Bearing Holder Drum Stopper Spring Check the drum stopper and spring for damage, or change shape.
  • Page 119 .TRANSMISSION SYSTEM VENOX Bolts Remove the eleven lower crankcase attaching bolts. Separate the upper and lower crankcase halves. Slightly tap the crankcase to separate the crankcase halves using a plastic hammer. Clip Remove the main/counter shaft ball bearing clip. Be careful not to lose the ball bearing clip.
  • Page 120 .TRANSMISSION SYSTEM VENOX Transmission Fork Remove the transmission fork shaft and transmission forks. Remove the transmission drum. Transmission Drum INSPECTION TRANSMISSION FORK/DRUM Inspect each transmission fork for bending or damage. Measure each transmission fork claw thickness. Service Limit: 5.0mm replace if below Measure each transmission fork shaft hole I.D.
  • Page 121 .TRANSMISSION SYSTEM VENOX Left Center Right INSTALLATION The installation sequence is the reverse of removal. Transmission fork make is as follows R(right),C(center),L(left). Main Shaft TRANSMISSION GEARS REMOVAL Remove the transmission main shaft and counter shaft from the upper crankcase. When removing, the transmission gears must be removed as a set.
  • Page 122 .TRANSMISSION SYSTEM VENOX Measure each shaft collar I.D./O.D. Service Limits: Main shaft 4th gear collar I.D.22.081mm replace if over Main shaft 4th gear collar O.D.24.919mm replace if below Main shaft 5th gear collar O.D.24.927mm replace if below Countershaft 1st gear collar I.D.20.081mm replace if over Countershaft 1st gear collar O.D.22.919mm replace if below...
  • Page 123 .TRANSMISSION SYSTEM VENOX BEARING REPLACEMENT Remove the main shaft and countershaft bearings from the main shaft and countershaft using a bearing remover. Special Bearing Remover Bearing Remover Drive the new bearing into the shaft using a bearing driver. • The flange of the oil seal should fix in the groove of the upper crankcase.
  • Page 124 .TRANSMISSION SYSTEM VENOX INSTALLATION The installation sequence is the reverse of removal. 10-11...
  • Page 125 . COOLING SYSTEM VENOX SCHEMATIC DRAWING 0.8~1.2kg-m 11-0...
  • Page 126 . COOLING SYSTEM VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ COOLING SYSTEM __________________________________________________________________________________ SERVICE INFORMATION------------------------------------------------ 11- 2 TROUBLESHOOTING----------------------------------------------------- 11- 2 COOLING SYSTEM TESTING------------------------------------------- 11- 4 RADIATOR REMOVAL --------------------------------------------------- 11- 4 THERMOSTATIC SWITCH INSPECTMENT ------------------------- 11- 6 WATER PUMP -------------------------------------------------------------- 11- 7 THERMOSENSOR---------------------------------------------------------- 11- 8 THERMOSTAT-------------------------------------------------------------- 11- 8 11-1...

  • Page 127: Cooling System

    . COOLING SYSTEM VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • The engine must be cool before servicing the cooling system. When the coolant temperature is over 100 , never remove the radiator cap to release the pressure because the boiling coolant may cause danger. •...
  • Page 128 . COOLING SYSTEM VENOX SPECIFICATIONS Radiator cap relief pressure 0.9±0.15kg/cm² Begins to open 80±2 Thermostat temperature Full-open Valve lift 3.5～4.5mm Radiator: 560cc Coolant capacity Total system 1030cc Reserve tank: 240cc COOLANT GRAVITY Temp. Coolant concentration 1.009 1.009 1.008 1.008 1.007 1.006 1.005 1.003 1.001 0.009 0.997 1.018 1.107 1.017 1.016 1.015 1.014 0.013 1.011 1.009 1.007 1.005 1.028 1.027 1.026 1.025 1.024 1.022 1.020 1.018 1.016 1.014 1.012 1.036 1.035 1.034 1.033 1.031 1.029 1.027 1.025 1.023 1.021 1.019...
  • Page 129 . COOLING SYSTEM VENOX Radiator Tester COOLING SYSTEM TESTING RADIATOR CAP INSPECTION Install the radiator cap onto the radiator tester and apply specified pressure to it. It must hold specified pressure for at least six seconds. Apply water to the cap sealing surface before testing.
  • Page 130 . COOLING SYSTEM VENOX Loosen the hose band and disconnect the upper hose from the radiator. Upper Hose Disconnect the thermostatic switch wire Fan Motor Wire Coupler coupler. Disconnect the fan motor wire coupler. Thermostatic Switch Wire Coupler Remove the two bolts on the radiator. Bolts Bolts RADIATOR DISASSEMBLY...
  • Page 131 . COOLING SYSTEM VENOX FAN MOTOR INSPECTMENT Check fan motor by battery. THERMOSTATIC SWITCH INSPECTMENT When coolant temperature lower then 90±2 the thermostatic switch OFF. When coolant temperature over 90±2 thermostatic switch ON. RADIATOR INSTALLATION The installation sequence is the reverse of removal.

  • Page 132: Water Pump

    . COOLING SYSTEM VENOX WATER PUMP MECHANICAL SEAL (WATER SEAL) INSPECTION Inspect the telltale hole for signs of mechanical seal coolant leakage. If the mechanical seal is leaking, remove the water pump. Water Pump Telltale Hole Outlet Cupreous Iron Pipe WATER PUMP REMOVAL Remove the coolant inlet hose and outlet cupreous iron pipe.
  • Page 133 . COOLING SYSTEM VENOX Thermosensor THERMOSENSOR THERMOSENSOR REMOVAL Remove the seat, fuel tank and left/right side cover. Drain the coolant. Disconnect the thermosensor wire. Remove the thermosensor. Thermosensor Wire Thermosensor THERMOSENSOR INSPECTION Suspend the thermosensor in a pan of water over a burner and measure the resistance through the sensor as the water heats up.
  • Page 134 . COOLING SYSTEM VENOX Bolts Remove the two bolts and separate the thermostat housing halves. Torgue: 0.8~1.2 kg-m Thermostat Thermostat Remove the thermostat from the thermostat housing. THERMOSTAT INSPECTION Thermostat Suspend the thermostat in a pan of water over a burner and gradually raise the water temperature to check its operation.
  • Page 135 . COOLING SYSTEM VENOX THERMOSTAT INSTALLATION The installation sequence is the reverse of removal. Replace the O-ring with a new one and apply sealant to it. Fill the radiator system with the specified coolant. Thermostat Housing 11-10...
  • Page 136 . FRONT WHEEL/SUSPENSION/STEERING VENOX 6.0~8.0kg-m 1.7~2.1kg-m 0.15~0.25kg-m 2.4~3.0kg-m 6.0~8.0kg-m 12-0...
  • Page 137 . FRONT WHEEL/SUSPENSION/STEERING VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ FRONT WHEEL/SUSPENSION/STEERING __________________________________________________________________________________ SERVICE INFORMATION ..............12- 2 TROUBLESHOOTING ............... 12- 3 HANDLEBAR..................12- 4 FRONT WHEEL .................. 12- 6 FRONT FORK ..................12-10 STEERING STEM ................12-11 12-1...
  • Page 138 . FRONT WHEEL/SUSPENSION/STEERING VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS SPECIFICATIONS Item Standard (mm) Service Limit (mm) ⎯ Front axle shaft runout ⎯ Axial Front wheel rim runout ⎯ Radial ⎯ Front fork spring free length 334.5 ⎯ Front fork tube runout ⎯...
  • Page 139 . FRONT WHEEL/SUSPENSION/STEERING VENOX TROUBLESHOOTING Hard steering • Insufficient tire pressure • Excessively tightened steering stem nut • Damaged steering stem bearings • Damaged steering stem bearing races Steers to one side or does not track straight • Uneven front shock absorbers •...
  • Page 140 . FRONT WHEEL/SUSPENSION/STEERING VENOX Throttle Housing HANDLEBAR REMOVAL Remove two screws attaching the throttle housing and the throttle housing. Screws Master Cylinder Throttle Pipe Disconnect the throttle cable from the throttle grip and then remove the throttle pipe from the handlebar. Throttle Cable Bolts Remove the two master cylinder holder...
  • Page 141 . FRONT WHEEL/SUSPENSION/STEERING VENOX Upper Fork Bridge Remove the four upper fork bridge bolts to remove the handlebar. Bolts INSTALLATION Place the handlebar on the upper fork bridge seat. Install the upper fork bridge set plates onto the handlebar. First tighten the front bolts and then the rear bolts.

  • Page 142: Front Wheel

    . FRONT WHEEL/SUSPENSION/STEERING VENOX THROTTLE PIPE INSTALLATION Clean the handlebar surface and install the throttle pipe. Check the throttle grip for proper operation. Connect the throttle cable to the throttle grip. Apply grease to the throttle cable. Install the throttle housing by aligning the pin on the housing with the punch hole in the handlebar.
  • Page 143 . FRONT WHEEL/SUSPENSION/STEERING VENOX INSPECTION Set the axle in V blocks and measure the runout. Service Limit: 0.2mm replace if over WHEEL RIM INSPECTION Place the front wheel in a turning stand. Spin the wheel by hand and measure the rim runout by using a dial gauge.
  • Page 144 . FRONT WHEEL/SUSPENSION/STEERING VENOX Axle Collar Remove the axle collar and dust seal from the right side of the wheel. Remove the dust seal. Bolts Remove the six bolts and the brake disk. Dust Seal Bearing Remover Drive out the wheel bearings and distance collar.
  • Page 145 . FRONT WHEEL/SUSPENSION/STEERING VENOX Dust Seal Install the brake disk and tighten the six bolts. Apply grease to the dust seal and install it. Brake Disk Groove Install the speedometer gearbox by aligning the tabs with the grooves. Flange Tab Speedometer Gearbox Apply grease to the speedometer gearbox and dust seal, then install them to the wheel...

  • Page 146: Front Fork

    . FRONT WHEEL/SUSPENSION/STEERING VENOX Groove INSTALLATION Install the front wheel onto the front fork, aligning the tab on the front fork with the groove in the speedometer gearbox. Speedometer Cable Insert the axle shaft and tighten the axle nut. Torque: 6.0～8.0kg-m Connect the speedometer cable and secure it with the screw.
  • Page 147 . FRONT WHEEL/SUSPENSION/STEERING VENOX Brake Caliper Bolts Remove the two bolts attaching the brake caliper holder. Remove the two headlight holder screws. Signal Light Holder Upper Fork Bridge Mount Bolt Remove the upper fork bridge mount bolt. Screw Remove the turn signal light holder screw. Remove the lower fork bridge mount bolt and then remove the right and left front forks.
  • Page 148 . FRONT WHEEL/SUSPENSION/STEERING VENOX BOTTOM CONE RACE REPLACEMENT Drive out the bottom cone race. Drive in a new bottom cone race onto the steering stem. Bottom Cone Race Top Cone Race STEERING STEM INSTALLATION Apply grease to the top and bottom ball races and steel balls.
  • Page 149 . REAR WHEEL/BRAKE/SUSPENSION VENOX 3.5~4.5kg-m 8.0~10.0kg-m 0.8~1.2kg-m 3.0~4.0kg-m 6.0~8.0kg-m 2.4~3.0kg-m 3.5~4.5kg-m 13-0...
  • Page 150 . REAR WHEEL/BRAKE/SUSPENSION VENOX __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ REAR WHEEL/BRAKE/SUSPENSION __________________________________________________________________________________ SERVICE INFORMATION ..............13- 2 TROUBLESHOOTING ............... 13- 3 REAR WHEEL..................13- 4 REAR BRAKE ..................13- 6 REAR SHOCK ABSORBER............... 13- 9 REAR FORK..................13- 9 REAR Fender ..................13-10 13-1...
  • Page 151 . REAR WHEEL/BRAKE/SUSPENSION VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • When installing the drive chain joint clip, the cutout of the clip should be opposite to the rotating direction. • After the drive chain is adjusted, make sure that the rear brake pedal free play is normal and adjust it if necessary.
  • Page 152 . REAR WHEEL/BRAKE/SUSPENSION VENOX TROUBLESHOOTING Rear wheel wobbling Poor brake performance • Bent rim • Improperly adjusted brake • Worn rear wheel bearing • Worn brake linings • Loose or broken wheel spoke wires • Contaminated or damaged brake linings •...

  • Page 153: Rear Wheel

    . REAR WHEEL/BRAKE/SUSPENSION VENOX Rear Brake Panel REAR WHEEL REMOVAL Remove the rear axle nut. Remove the rear brake adjusting nut. Rear Brake Adjusting Nut Rear Axle Nut Remove the rear brake panel fixing arm bolt. Remove the bushing. Remove the rear brake panel. Loose both of the chain adjuster nut.
  • Page 154 . REAR WHEEL/BRAKE/SUSPENSION VENOX Check the wheel bearing play by placing the wheel in a turning stand and spinning the wheel by hand. Axial Radial Check the drive chain gear teeth for wear or damage. Replace the drive chain gear if necessary. Replace Good If the drive chain gear teeth are worn or...

  • Page 155: Rear Brake

    . REAR WHEEL/BRAKE/SUSPENSION VENOX ASSEMBLY Pack all bearing cavities with grease. Drive in the left bearing. Install the distance collar. Drive in the right bearing. • Drive in the bearings squarely. • Install the bearings with the sealed end facing out. Special Bearing driver handle Attachment,37×40mm...
  • Page 156 . REAR WHEEL/BRAKE/SUSPENSION VENOX Measure the brake drum I.D. Service Limit: 161.3mm replace if over DISASSEMBLY Brake Remove the springs and brake shoes. Springs Brake Cam Remove the brake arm bolt to remove the brake arm. Remove the dust seal. Remove the brake cam.
  • Page 157 . REAR WHEEL/BRAKE/SUSPENSION VENOX Brake Cam Apply grease to the brake cam and anchor pin, then install the brake cam to the brake panel. Apply engine oil to the dust seal and install it to the brake cam. Install the wear indicator plate on the brake cam, aligning the mark on the plate with the groove on the brake cam.

  • Page 158: Rear Shock Absorber

    . REAR WHEEL/BRAKE/SUSPENSION VENOX Upper Mount REAR SHOCK ABSORBER REMOVAL/INSTALLATION Remove the shock absorber upper mount nuts and washers and then press down the motorcycle to pull out the shock absorbers. Remove the shock absorber lower mount bolts to remove the rear shock absorbers. INSTALLATION The installation sequence is the reverse of removal.
  • Page 159 . REAR WHEEL/BRAKE/SUSPENSION VENOX REAR FENDER REMOVAL Remove the rear carrier. Disconnect the turn signal light, rear stop light and taillight wires. Remove the right and left side cover bolts and then remove the two upper lock bolts to remove the rear fender. When installing, connect and route the taillight and turn signal light wires properly.
  • Page 160 . HYDRAULIC BRAKE VENOX 0.8~1.2kg-m 3.0~4.0kg-m 2.4~3.0kg-m 14-0...

  • Page 161: Hydraulic Brake

    . HYDRAULIC BRAKE VENOX HYDRAULIC BRAKE SERVICE INFORMATION ..............14- 2 TROUBLESHOOTING ............... 14- 3 BRAKE FLUID CHANGE/AIR BLEED..........14- 4 BRAKE PAD/DISK ................14- 5 BRAKE MASTER CYLINDER ............14- 6 BRAKE CALIPER ................14- 8 14-1...

  • Page 162: Hydraulic Brake

    . HYDRAULIC BRAKE VENOX SERVICE INFORMATION GENERAL INSTRUCTIONS • Drain the brake fluid from the hydraulic brake system before disassembly. • Do not allow any foreign matters entering the brake reservoir when filling the brake reservoir with brake fluid. • Be careful not to splash brake fluid on any coated surfaces and instrument covers to avoid damage.
  • Page 163 . HYDRAULIC BRAKE VENOX TROUBLESHOOTING Loose brake lever • Air in hydraulic brake system • Brake fluid level too low • Hydraulic brake system leakage Tight brake lever • Seized piston • Clogged hydraulic brake system • Smooth or worn brake pad Hard braking •...
  • Page 164 . HYDRAULIC BRAKE VENOX Screws BRAKE FLUID CHANGE/AIR BLEED Place the motorcycle on its main stand on level ground and set the handlebar upright. Remove the two screws attaching the brake fluid reservoir cap. Use towel to cover plastic parts and coated surfaces to avoid damage caused by splash of brake fluid.
  • Page 165 . HYDRAULIC BRAKE VENOX Bolts BRAKE PAD/DISK BRAKE PAD REPLACEMENT Remove the two bolts attaching the brake caliper holder. The brake pads can be replaced without removing the brake fluid tube. Remove the brake caliper. Remove the brake pad pin bolt and then Brake Caliper remove the pad pin bolt and brake pads.
  • Page 166 . HYDRAULIC BRAKE VENOX BRAKE DISK Measure the brake disk thickness. Service Limit: 3.0mm Measure the brake disk runout. Service Limit: 0.3mm BRAKE MASTER CYLINDER REMOVAL Drain the brake fluid from the hydraulic Fluid Tube brake system. Do not splash brake fluid onto any rubber, plastic and coated parts.
  • Page 167 . HYDRAULIC BRAKE VENOX INSPECTION Measure the brake master cylinder I.D. Inspect the master cylinder for scratches or cracks. Service Limit: 12.75mm replace if over Measure the brake master cylinder piston O.D. Service Limit: 12.64mm replace if below ASSEMBLY Before assembly, apply brake fluid to all removed parts.

  • Page 168: Brake Caliper

    . HYDRAULIC BRAKE VENOX Place the brake master cylinder on the handlebar and install the master cylinder holder with the “UP” mark facing up, aligning the tab on the holder with the hole in the handlebar. First tighten the upper bolt and then tighten the lower bolt.
  • Page 169 . HYDRAULIC BRAKE VENOX Compressed Air Remove the pistons from the brake caliper. Use compressed air to press out the pistons through the brake fluid inlet opening and place a towel under the caliper to avoid contamination caused by the removed pistons.
  • Page 170 . HYDRAULIC BRAKE VENOX ASSEMBLY Clean all removed parts. Apply silicon grease to the pistons and oil seals. Lubricate the brake caliper cylinder inside wall with brake fluid. Install the oil seals and then install the brake caliper pistons with the grooved side facing out.
  • Page 171 . IGNITION SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ IGNITION SYSTEM __________________________________________________________________________________ SERVICE INFORMATION ..............15-2 TROUBLESHOOTING ............... 15-3 IGNITION COIL.................. 15-4 CDI UNIT..................... 15-5 PULSER COIL ..................15-6 15-0...

  • Page 172: Ignition System

    . IGNITION SYSTEM Battery Ignition Switch Ignition Coil Pulser Coil 15-1...
  • Page 173 . IGNITION SYSTEM SERVICE INFORMATION GENERAL INSTRUCTIONS • Inspect the ignition system according to the sequence specified in the Troubleshooting 15-3. • The ignition system has a CPU in the CDI unit, so the ignition timing is not adjustable. • Do not drop or impact the CDI unit with strong force to avoid damage. Be careful when removing it.
  • Page 174 . IGNITION SYSTEM TROUBLESHOOTING Engine stalls immediately after it starts • Weak spark • Improper ignition timing • Faulty CDI unit No spark at plug • Faulty ignition switch • Poorly connected, broken or shorted wire −Between pulser coil, CDI unit and ignition coil −Between exciter coil and CDI unit −Between CDI unit and ignition coil −Between CDI unit and ignition switch...
  • Page 175 . IGNITION SYSTEM Ignition Coil IGNITION COIL CONTINUITY TEST Disconnect the ignition coil primary wire coupler and measure the resistance between the ignition coil primary wire terminals. Resistance: 3.57Ω~4.83Ω Spark Plug Cap Measure the secondary coil resistance between the spark plug wire and the primary coil terminal.
  • Page 176 . IGNITION SYSTEM CDI UNIT CDI Unit INSPECTION Disconnect the CDI unit coupler. Check for continuity with the coupler on the hardness wire side and CDI unit. Inspection table is as follows. The CDI unit is fully transistorized. For accurate testing, it is necessary to use a specified tester.
  • Page 177 . IGNITION SYSTEM PULSER COIL INSPECTION Disconnect the pulser coil wire coupler and measure the resistance between the blue/ yellow and green/white wire terminals. Resistance: 396～594Ω Picture C Picture D 15-6...
  • Page 178 . CHARGING SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ CHARGING SYSTEM __________________________________________________________________________________ SERVICE INFORMATION ..............16-2 TROUBLESHOOTING ............... 16-3 BATTERY.................... 16-4 BATTERY CHARGING..............16-4 A.C. GENERATOR ................16-5 REGULATOR/RECTIFIER..............16-5 16-0...

  • Page 179: Charging System

    . CHARGING SYSTEM REG/REC Ignition Switch 16-1...
  • Page 180 • When inspecting the A.C. generator, use an electric tester. • Route the charging system wires properly to avoid short-current due to wires being twisted or kinked. SPECIFICATIONS VENOX 250 Battery capacity 12V8AH Battery Electrolyte specific gravity 1.32...
  • Page 181 . CHARGING SYSTEM TROUBLESHOOTING No power • Dead battery • Low fluid level • Disconnected battery cable • Faulty ignition switch Low power • Weak battery • Loose battery connection (terminal) • Charging system failure • Faulty regulator/rectifier Intermittent power •...

  • Page 182: Battery Charging

    . CHARGING SYSTEM BATTERY REMOVAL Remove the seat. Remove the left side cover. First disconnect the battery negative cable and then the positive cable. Remove the two battery set plate lock nuts. BATTERY CHARGING Connect the charger positive cable to the battery positive cable.
  • Page 183 . CHARGING SYSTEM LIMIT VOLTAGE TEST: Start the engine and gradually increase the engine speed to measure the limit voltage. Limit Voltage: 14.5±0.5V/5000rpm Note: Test when the battery is fully charged. When testing the limit voltage, also use a tachometer for operation. A.C.
  • Page 184 . CHARGING SYSTEM INSPECTION Remove the regulator/rectifier wire coupler. Normal Red/White Direction Check the continuity between the wire terminals. Normal Direction: Continuity (+) Probe (-) Probe Yellow Green Red/White Yellow Reverse Direction Green Reverse Direction: No Continuity (+) Probe (-) Probe Green Yellow Yellow...
  • Page 185 . STARTING SYSTEM __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ STARTING SYSTEM __________________________________________________________________________________ SERVICE INFORMATION ..............17-2 TROUBLESHOOTING ............... 17-2 STARTER MOTOR ................17-3 STARTER RELAY ................17-4 CLUTCH DIODE................. 17-4 17-0...

  • Page 186: Starting System

    . STARTING SYSTEM Engine Stop Switch Clutch Diode Neutral Switch Side Stand Switch Starter Motor 17-1...
  • Page 187 . STARTING SYSTEM SERVICE INFORMATION GENERAL INSTRUCTIONS • The removal of starter motor can be accomplished with the engine installed in the frame. • When connecting the starting system wires, connect them securely to avoid hard starting due to poor connection. TROUBLESHOOTING Starter motor won’t turn Lack of power...

  • Page 188: Starter Motor

    . STARTING SYSTEM STARTER MOTOR REMOVAL Remove the two starter motor mounting bolts and the motor. Before removing the starter motor, turn the ignition switch OFF and remove the battery ground. Then, turn the ignition switch on to check if the starter motor operates properly.

  • Page 189: Starter Relay

    . STARTING SYSTEM STARTER RELAY INSPECTION Turn the ignition switch ON and the starter relay is normal if you hear a “click” when the starter button is depressed. If there is no click sound: • Inspect the starter relay voltage •...
  • Page 190 . LIGHTS/INSTRUMENT/SWITCHES/HORN __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ __________________________________________________________________________________ LIGHTS/INSTRUMENT/SWITCHES/HORN __________________________________________________________________________________ SERVICE INFORMATION ..............18-1 TROUBLESHOOTING ............... 18-1 HEADLIGHT/INSTRUMENT ............18-2 TURN SIGNAL LIGHT............... 18-3 STOP LIGHT/TAIL LIGHT ..............18-3 IGNITION SWITCH................18-3 STARTER BUTTON/HORN BUTTON / FUEL GAUGE....18-4 HANDLEBAR SWITCHES..............18-5 FUEL UNIT..................
  • Page 191 . LIGHTS/INSTRUMENT/SWITCHES/HORN SERVICE INFORMATION GENERAL INSTRUCTIONS • All plastic plugs have locking tabs that must be released before disconnecting. • An electric tester must be used for checking the continuity between two points. The electric tester also contains a voltmeter which can be used to measure voltage. •...
  • Page 192 . LIGHTS/INSTRUMENT/SWITCHES/HORN HEADLIGHT REMOVAL Remove the left sides of attaching bolts and screws on headlight fairing to dismantle the fairing. Remove the headlight unit and disconnect the headlight wire coupler. Screws Bulb Bulb Socket Remove the headlight bulb and bulb socket. Check the bulb for damage and replace with a new one if necessary.
  • Page 193 . LIGHTS/INSTRUMENT/SWITCHES/HORN Bulb TURN SIGNAL LIGHT Remove the turn signal light shell and the bulb. Check the bulb for damage and replace with a new one if necessary. The installation sequence is the reverse of removal. STOP LIGHT/TAIL LIGHT Remove the two taillight shell screws and the shell.
  • Page 194 . LIGHTS/INSTRUMENT/SWITCHES/HORN INSPECTION Check for continuity between the wires indicated below. Color Black Red/White Position STARTER BUTTON Disconnect the right switch wire coupler. Check for continuity between the black/white and yellow/red wires. Color Black/White Yellow/Red Position FREE PUSH Starter Switch Coupler HORN BUTTON Disconnect the left switch wire coupler.
  • Page 195 . LIGHTS/INSTRUMENT/SWITCHES/HORN HORN The horn is normal if it sounds when a 12V battery is connected across the horn wire terminals. Replace the horn if it does not sound. Horn FUEL GAUGE Disconnect the fuel gauge and fuel unit wire couplers. Connect the fuel gauge green wire with the yellow/white wire.
  • Page 196 . LIGHTS/INSTRUMENT/SWITCHES/HORN REAR STOP SWITCH Remove the right side cover. Disconnect the rear stop switch wire coupler. Check for continuity between the rear stop switch wires. Brake pedal depressed: Continuity. Brake pedal released: No continuity. Rear Brake TURN SIGNAL SWITCH Switch Turn Signal Coupler...
  • Page 197 . LIGHTS/INSTRUMENT/SWITCHES/HORN ENGINE STOP SWITCH Disconnect the engine stop switch wire coupler. Check for continuity between the engine stop switch wires. Color Black/White Black/Green Position Switch Engine Stop Coupler DIMMER SWITCH Disconnect the dimmer switch wire coupler. Check for continuity between the dimmer switch wires.
  • Page 198 . LIGHTS/INSTRUMENT/SWITCHES/HORN INSPECTION Check the fuel unit O-ring for wear, damage or deformation. Replace if necessary. Measure the continuity between the fuel unit wire terminals with the float at the upper (Full) and lower (Empty) positions. Resistances: Upper (Full): No continuity Lower (Empty): Continuity Connect the fuel unit wire coupler to the wire harness and turn the ignition switch...
  • Page 199 . LIGHTS/INSTRUMENT/SWITCHES/HORN THROTTLE POSITION SENSOR Disconnect the throttle position sensor wire coupler on carburetor. Check for the resistance among three wires of the throttle position sensor. Unit:KΩ 0~5±1 0~5±1 Throttle Position Sensor SIDE STAND SWITCH Disconnect the side stand switch wire Side Stand Switch Wire Coupler coupler.

This manual is also suitable for:

Venox 250

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