No photo of this model in the library yet.

Have this bike? Send a photo or the manual's service chart

Hyosung · Overhead-cam four-stroke single, wet sump, gearbox shares engine oil, chain drive

GF 125

Library entry covers 2000-2006

30 factory 51 guideline

Published source

Hyosung GF125 Service Manual 99000-94200, periodic maintenance and lubrication charts pp.2-1 to 2-2 (ManualsLib 722922 pages 17-18)

Factory service manual. Covers Hyosung GF 125 service manual 99000-94200 (cover prints GF 125); no year printed.

81 items for a 2001 model, grouped by interval the way a factory chart is laid out.

How this bike is built (what the schedule is based on)

Engine cycle: Four-stroke
Engine lubrication: Wet sump (oil in crankcase)
Oil filtration: Replaceable cartridge or spin-on filter
Valve gear: Overhead cam, screw/locknut adjusters
Ignition: Electronic (CDI / transistor / ECU)
Charging: Alternator / stator with rectifier
Battery: Wet cell (flooded lead-acid, needs topping up)
Fuel system: Single carburetor
Cooling: Air / oil cooled
Primary drive: Gear or chain inside engine, shares engine oil
Gearbox oil: Shares engine oil
Clutch control: Hand lever, cable
Final drive: Chain
Front suspension: Telescopic fork
Rear suspension: Swingarm, twin shocks
Front brake: Disc, hydraulic
Rear brake: Drum (or band / belt rim)
Wheels: Spoked, tubed
Sidecar: No sidecar

Maintenance schedule

2001 Hyosung GF 125

On the road: every 300 km

1 item

Check engine oil level

Pre-ride / on the road

Guideline

Each fuel stop on old machines. Dry sump: check the tank hot, engine idling or just stopped, per your manual.

On the road: every 500 km

3 items

Check lights, horn, brake light switches

Pre-ride / on the road

Guideline
Check tire pressures

Pre-ride / on the road

Guideline
Lubricate drive chain

Pre-ride / on the road

Guideline

Lube warm, ideally at the end of the riding day so it soaks in overnight. Sooner after rain.

On the road: every 1,000 km

1 item

Check chain slack and rear wheel alignment

Pre-ride / on the road

Guideline

Every 1,000 km

2 items

Drive chain (inspect and clean)

Final drive

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect and clean every 1,000 km.
Drive chain (lubricate)

Final drive

Factory

Factory: Lubrication chart (service manual p.2-2; columns initial 1,000 km and every 5,000 km, every 10,000 km): motor oil every 1,000 km.

Every 1,600 km or 6 months

2 items

Adjust rear drum brake and rod / cable linkage

Brakes

Guideline
Inspect tire tread, sidewalls and date codes

Wheels and tires

Guideline

Every 3,000 km

1 item

Air cleaner element (clean)

Fuel and air

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): clean every 3,000 km.

Every 5,000 km or 12 months

11 items

Check throttle cable(s) free play and return

Fuel and air

Guideline
Clean fuel tap filter / sediment bowl

Fuel and air

Guideline
Clean drive chain thoroughly (remove and soak, re-lube)

Final drive

Guideline

Non O-ring chains on old machines: remove, clean, soak in hot chain grease or lube, refit with the master link clip closed end leading.
Inspect chain and sprockets for wear (measure stretch)

Final drive

Guideline
Check steering head bearing adjustment

Front end

Guideline
Inspect fork seals, stanchions and fork boots

Front end

Guideline
Check footrests, pegs, rear brake and gear lever pivots

Rear suspension and frame

Guideline
Grease and check center / side stand and springs

Rear suspension and frame

Guideline
Check brake pads and discs

Brakes

Guideline
Check spoke tension and wheel true

Wheels and tires

Guideline
Check wheel bearings for play

Wheels and tires

Guideline

Every 5,000 km

18 items

Chassis bolts and nuts (inspect)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Compression pressure (inspect)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Cylinder head nuts, cylinder nuts, exhaust pipe bolts and nuts (inspect)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Engine oil (change)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): change at the initial 1,000 km and every 5,000 km.
Engine oil filter (replace)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): replace at the initial 1,000 km and every 5,000 km.
Oil pressure (inspect)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect every 5,000 km.
Spark plug (inspect)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Valve clearance (inspect)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Carburetor (inspect)

Fuel and air

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Fuel line (inspect)

Fuel and air

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Battery (inspect)

Ignition and electrics

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Clutch (inspect)

Primary and gearbox

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Steering (inspect)

Front end

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Brake hose (inspect)

Brakes

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Brake pedal (grease or oil)

Brakes

Factory

Factory: Lubrication chart (service manual p.2-2; columns initial 1,000 km and every 5,000 km, every 10,000 km): grease or oil at the initial 1,000 km and every 5,000 km.
Brakes (inspect)

Brakes

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.
Throttle, clutch and brake cables (lubricate)

Brakes

Factory

Factory: Lubrication chart (service manual p.2-2; columns initial 1,000 km and every 5,000 km, every 10,000 km): motor oil at the initial 1,000 km and every 5,000 km.
Tires (inspect)

Wheels and tires

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): inspect at the initial 1,000 km and every 5,000 km.

Every 6,500 km or 12 months

3 items

Inspect, clean and gap spark plugs

Engine

Guideline
Adjust clutch free play, lubricate cable and lever pivot

Primary and gearbox

Guideline
Lubricate brake cam spindles, check linings and drums

Brakes

Guideline

Every 8,000 km or 12 months

2 items

Change engine oil

Engine

Guideline

Pre-1970 machines: many owners run non-detergent or classic-spec oil with no filter, so short intervals matter. Dry sump: drain the tank and the crankcase/sump, flush the tank and clean the feed and return screens.
Replace oil filter

Engine

Guideline

Every 9,500 km or 12 months

7 items

Clean / inspect air filter

Fuel and air

Guideline

Mesh or oiled foam: clean and re-oil. Paper: blow out or replace. Some very early machines have no filter at all.
Clean carburetor float bowl(s), check float level and jets

Fuel and air

Guideline

Ethanol fuel varnishes old carbs quickly in storage.
Check charging voltage and regulator / cut-out

Ignition and electrics

Guideline
Check swingarm bushes for play

Rear suspension and frame

Guideline
Inspect rear shocks for leaks and damping

Rear suspension and frame

Guideline
Lubricate control cables and lever pivots

Controls and cables

Guideline
Lubricate speedometer / tachometer cables, check drive

Controls and cables

Guideline

A dry speedo cable whips the needle and eventually kills the instrument.

Every 10,000 km

5 items

Oil sump filter (clean)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): clean every 10,000 km.
Spark plug (replace)

Engine

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): replace every 10,000 km.
Fuel strainer (clean)

Fuel and air

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): clean at the initial 1,000 km and every 10,000 km.
Front fork oil (change)

Front end

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): change at the initial 1,000 km and every 10,000 km.
Throttle grip, speedometer cable, speedometer gear box and brake cam shaft (grease)

Brakes

Factory

Factory: Lubrication chart (service manual p.2-2; columns initial 1,000 km and every 5,000 km, every 10,000 km): grease every 10,000 km.

Every 13,000 km or 2 years

1 item

Check and adjust valve clearances

Engine

Guideline

Every 16,000 km or 2 years

1 item

Compression test (or leak-down)

Engine

Guideline

Every 19,500 km or 2 years

2 items

Replace air filter element

Fuel and air

Guideline
Grease swingarm pivot

Rear suspension and frame

Guideline

Every 20,000 km or 2 years

1 item

Steering stem and swing arm bearings (grease)

Front end

Factory

Factory: Lubrication chart (service manual p.2-2; columns initial 1,000 km and every 5,000 km, every 10,000 km): grease every 2 years or 20,000 km.

Every 24,000 km or 3 years

1 item

Change fork oil

Front end

Guideline

Some early telescopic forks are grease filled or use very small oil quantities. Check your manual.

Every 24,000 km

1 item

Replace brake linings / skim drums (wear based)

Brakes

Guideline

Every 25,500 km or 4 years

1 item

Replace spark plugs

Engine

Guideline

Every 29,000 km

1 item

Replace chain and sprockets (wear based)

Final drive

Guideline

Every 32,000 km or 4 years

2 items

Repack / replace steering head bearings

Front end

Guideline

Many old machines use loose balls in cups and cones. Taper roller conversions are common.
Repack / replace wheel bearings

Wheels and tires

Guideline

Cup-and-cone and taper roller hubs need periodic repacking and adjustment.

Every 40,000 km or 6 years

1 item

Replace swingarm bushes / bearings

Rear suspension and frame

Guideline

Every 48,500 km or 6 years

1 item

Rebuild forks: seals, bushes, springs

Front end

Guideline

Every 6 months

1 item

Clean battery terminals, check charge and strap

Ignition and electrics

Guideline

Every 2 years

4 items

Inspect wiring, bullet connectors and ground points

Ignition and electrics

Guideline
Inspect frame, welds and lugs for cracks

Rear suspension and frame

Guideline
Brake fluid (change)

Brakes

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): change every 2 years.
Replace brake fluid

Brakes

Guideline

Every 4 years

5 items

Fuel line (replace)

Fuel and air

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): replace every 4 years.
Replace fuel lines

Fuel and air

Guideline

Old rubber and modern ethanol fuel do not mix well.
Brake hose (replace)

Brakes

Factory

Factory: Periodic maintenance chart (service manual p.2-1; columns initial 1,000 km, every 5,000 km, every 10,000 km): replace every 4 years.
Inspect brake hoses; replace old rubber

Brakes

Guideline
Rebuild calipers and master cylinders (seals)

Brakes

Guideline

Every 6 years

2 items

Replace inner tubes and rim tape with tires

Wheels and tires

Guideline
Replace tires on age (regardless of tread)

Wheels and tires

Guideline

Guideline lines: Intervals here are general guidelines for the machine's era and layout, compiled for this app. They are not factory manual figures. Check your workshop manual, and edit any interval in the bike's Schedule tab.