Hyosung Comet 250/125 (2002) Factory Service Manual (P/N 99000-94710)

This first-edition Hyosung factory service manual for the 2002 Comet 250 and Comet 125 (P/N 99000-94710) covers maintenance and repair for both carbureted V-twin models.

Printable PDF and Included Pages

Text search and wiring detail: Service text is searchable. The model-name logos and some diagram labels fall outside the searchable text. The PDF has no embedded bookmarks, and the smallest wiring labels are readable when enlarged.

The download is one printable, 163-page English PDF. The total includes 150 technical and reference pages, seven section contents pages, five opening pages including the cover, and one publication-details page.

V-Twin Teardown, Carburetor Service, and Chassis Repair

These selected workshop topics are part of the manual, which also includes lubrication-point illustrations and a special-tool list.

• Engine and driveline: Engine removal and refitting, wet multi-plate clutch disassembly, and transmission shaft removal. Internal engine coverage stops at teardown.

• Periodic maintenance: Step-by-step valve-clearance inspection and adjustment, drive-chain adjustment, fluid recommendations, and procedures for compression and oil-pressure testing.

• Fuel system: Fuel tank and fuel cock removal, dual-carburetor cleaning and float-height adjustment, and separate fuel-pump checks for each model.

• Electrical diagnosis: Ignition and charging tests, starter-motor overhaul, switch continuity checks, and side-stand ignition interlock circuits.

• Brakes and chassis: Disc brake caliper and master cylinder service, hydraulic bleeding, telescopic fork rebuilds, and service for wheel, steering-stem, and swingarm bearings.

• Workshop references: Model-specific wiring diagrams, wire and cable routing illustrations, troubleshooting tables, tightening torques, and component wear limits.

Hyosung wrote this manual for readers who already have the knowledge and skills to service its vehicles. It assumes familiarity with general workshop practices.

Engine Teardown and Coverage Limits

The teardown covers removal of the cylinder head covers, camshafts, pistons, and oil pump, as well as crankcase separation. The engine chapter ends at printed page 3-18. The indexed internal component inspection and engine reassembly sections are omitted from this PDF.

The manual identifies crankcase separator 09920-13120 and warns that separating the case from the wrong side can damage the gearshift cam stopper. Engine, clutch, and transmission service-data tables remain available, including separate gear ratios for the two models.

Maintenance and Engine Condition Checks

The periodic maintenance chart sets service intervals, while exterior illustrations and serial-number locations help identify the vehicle. The valve-clearance procedure addresses both cylinders and pairs with separate intake and exhaust shim selection charts.

The compression and oil-pressure procedures give model-specific reference values for assessing cylinder condition and investigating lubrication faults.

Carburetors and Fuel-Pump Differences

Carburetor service covers diaphragm and piston-valve assemblies, jets, needle valves, and float chambers. Separate jetting tables let you match specifications to the model and to the front or rear carburetor before reassembly.

The Comet 250 uses an electric fuel pump with pump and relay tests in the electrical chapter. The Comet 125 pump section shows the vacuum connection and hose routing.

Charging, Ignition, and Starting Diagnosis

The electrical chapter pairs circuit diagrams with regulator/rectifier, magneto, and ignition-coil checks. The switch continuity tables and interlock operating conditions help distinguish a starting-circuit fault from normal interlock operation.

Starter-motor service covers brush, commutator, and armature inspection, followed by reassembly.

Forks, Rear Shocks, and Brake Service

Separate front fork sections show the Comet 250 and Comet 125 assemblies, with exploded views, seal replacement, and fork oil-level procedures. The rear shock is a sealed service unit with procedures for removal, inspection, and replacement.

The brake chapter covers caliper bores, piston seals, and master cylinder inspection and reassembly. Hydraulic brake service requires workshop experience and suitable protective equipment. The manual warns that incompatible brake fluids can damage the system.

Valve Clearance and Mounting Torque Examples

On both models, cold valve clearance is 0.1–0.2 mm at the intake valves and 0.2–0.3 mm at the exhaust valves. These ranges accompany the clearance checks and shim selection charts.

The engine refitting procedure specifies 40–60 N·m for the engine mounting bolts, also listed in the engine tightening-torque table.