KYMCO VENOX 250 / 250i Service Manual, 2006 (P/N T100RB50AA)

KYMCO factory service manual P/N T100RB50AA, First Edition, December 2006, covers the carbureted VENOX 250 and the VENOX 250i with AFI (Automatic Fuel Injection). Its 19 technical sections cover periodic maintenance, mechanical repair, chassis service, and electrical diagnosis.

PDF Search, Bookmarks, and Wiring Detail

Search and diagram access: Text search works across the main service chapters, but labels within the final wiring diagrams are not searchable. Embedded bookmarks reach selected sections rather than every chapter. Small wiring labels require zooming; lettering in the 250i diagram is coarser than in the 250 diagram.

Supplied as one printable, 243-page PDF. This total includes the opening motorcycle image page, four title/edition/preface/contents pages, and the two final wiring-diagram pages.

Engine Teardown, Fuel-System Service, and Chassis Repair

These highlights show selected coverage, rather than the complete contents. Other topics include headlight aiming and clutch-switch continuity testing.

• Engine repair: Step-by-step procedures cover engine removal, cylinder-head disassembly, camshaft and rocker-arm service, crankcase separation, and crankshaft, piston, and cylinder inspection.

• Clutch and transmission: One-way starter clutch and wet multi-disc clutch service, gear-shift mechanism removal, transmission fork and drum inspection, and shaft-bearing replacement.

• Carburetor service: KEIHIN CVK removal and disassembly, vacuum-diaphragm inspection, air cut-off valve service, float-level checks, and twin-cylinder vacuum/CO adjustment.

• AFI diagnosis: CELP blink-code troubleshooting and PDA-based diagnostics, with component checks and removal procedures for the injection system.

• Cooling and lubrication: Cooling-system pressure testing, radiator removal, thermostat and water-pump inspection, plus oil-pump disassembly and clearance checks.

• Chassis and brakes: Wheel-bearing replacement, steering-stem service, suspension removal, rear drum-brake repair, hydraulic brake bleeding, and master-cylinder/caliper overhaul.

• Electrical testing: Ignition, charging, and starting-system troubleshooting, instrument and switch checks, cable-routing views, and separate wiring diagrams for both fuel-system variants.

Written for service personnel, this manual assumes familiarity with workshop procedures and the use of measuring equipment and special tools.

Internal Engine Inspection and Bearing Selection

Engine inspection data includes valve and guide wear, camshaft dimensions, cylinder-bore condition, piston-ring measurements, crankshaft runout, and connecting-rod clearances. The connecting-rod and crank-bearing selection tables match identification marks to Brown, Green, or Yellow bearing shells, supporting bearing selection during an internal rebuild.

The Generator/Left Crank Case Cover assembly views distinguish the two models. Component-specific torque tables include a cylinder-head bolt tightening table; the transmission section adds mainshaft/countershaft gear and collar measurements.

Carburetor and AFI Service Differences

Carbureted model: The KEIHIN CVK specifications distinguish front and rear main jets and float levels. Vacuum-chamber, float-chamber, and automatic fuel-valve procedures sit alongside carburetor synchronization and CO adjustment information.

Fuel-injected model: The AFI section covers the ECU, fuel pump and relay, front/rear injectors, WTS, O2/O2-heater sensor, MAP, T-MAP, TPS, ISC, tilt switch, crank-position sensing, and diagnostic connector. The AFI System Diagram and System Location views identify the components involved in fault tracing.

CELP diagnosis provides a route to reading and clearing fault codes without a scan tool. The separate PDA instructions describe KYMCO diagnostic-cable use with Dtool 5.0, including live signal data, idle CO adjustment, and component-function checks for the cooling-fan relay, check-engine lamp, and O2-heater relay.

The PDA, diagnostic cable, and software are external service equipment and are not included with the PDF.

Cooling, Suspension, and Brake Service

The Cooling System Schematic Drawing supports the radiator, thermostat, thermosensor, fan-switch, and water-pump sections. Reference data includes radiator-cap relief pressure, thermostat opening and lift specifications, coolant capacities, and temperature-dependent sensor resistance.

Chassis coverage distinguishes front disc and rear drum brakes. Inspection data includes disc thickness and runout, drum diameter, lining wear, wheel and axle runout, and suspension oil specifications. Front-fork coverage describes removal and installation; rear shock-absorber and rear-fork procedures address removal, installation, and related inspections.

Ignition, Charging, and Starting Circuits

Electrical references include ignition-coil primary/secondary resistance, pulser-coil checks, generator and regulator/rectifier tests, starter-relay diagnosis, and clutch-diode testing. The manual distinguishes charging output between the two models.

Cable & Harness Routing views, ignition and starting-system diagrams, and the final model-specific wiring diagrams support circuit tracing. Lighting, fuel-indicator, and handlebar-switch sections add continuity checks and connector references.

Special Tools and Repair Precautions

Tool references include flywheel holder E021 and puller E042, valve spring compressor E040, and piston installer E041. Clutch service identifies lifter holder E047 and lock-nut socket E046; bearing work references remover E030 and driver handle E014.

Vacuum/CO adjuster E043 and vacuum gauge E045 are identified for carburetor adjustment.

The manual warns that reversing the oil-filter screen can damage the engine and identifies a left-hand thread on the one-way clutch mounting bolt. For the 250i, it warns against disturbing the throttle body's painted adjustment screws or connecting/disconnecting the ECU with the ignition on, which can upset synchronization or damage the ECU.

Engine removal requires an engine stand or floor jack. Fuel-system work, hydraulic brake service, cooling-system pressure work, and electrical disconnection have dedicated safety precautions.

A Preview of Valve and Electrical Test Data

Valve-clearance specifications give 0.10 mm for both intake and exhaust with the engine cold, below 35°C.

Charging data specifies at least 10.5 A at 1500 rpm for the VENOX 250 and 11.5 A at the same speed for the VENOX 250i. The AFI injector inspection gives a resistance specification of 11.7 ± 0.6 Ω at 20°C.