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Yamaha · European two-stroke single (DKW, Jawa, CZ, MZ, Puch, Bultaco, Montesa, Ossa)

YS 125

Library entry covers 2018-2021

31 factory 36 guideline

Published source

Yamaha YS125-5C Owner's Manual BT4-F8199-E0 (English), Periodic maintenance charts pp.6-3 to 6-7

Factory owner's handbook. Covers 2017 (YS125-5C, EU owner's manual BT4-F8199-E0, printed Nov 2016).

Open the source

67 items for a 2018 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: Two-stroke
Engine lubrication: Two-stroke premix (oil in fuel)
Oil filtration: None (no filter)
Valve gear: None (two-stroke porting)
Ignition: Magneto (incl. magdyno, flywheel magneto)
Charging: Alternator / stator with rectifier
Battery: Wet cell (flooded lead-acid, needs topping up)
Fuel system: Fuel injection
Cooling: Air / oil cooled
Primary drive: Gear or chain inside engine, shares engine oil
Gearbox oil: Separate gearbox oil
Clutch control: Hand lever, cable
Final drive: Chain
Front suspension: Telescopic fork
Rear suspension: Swingarm, twin shocks
Front brake: Drum (or band / stirrup)
Rear brake: Drum (or band / belt rim)
Wheels: Spoked, tubed
Sidecar: No sidecar

Maintenance schedule

2018 Yamaha YS 125

On the road: every 150 mi

1 item

Check two-stroke oil tank / carry premix oil

Pre-ride / on the road

Guideline

Running a two-stroke out of oil seizes it. Injection bikes: check the tank. Premix: carry oil and a measure.

On the road: every 300 mi

2 items

Check lights, horn, brake light switches

Pre-ride / on the road

Guideline
Check tire pressures

Pre-ride / on the road

Guideline

On the road: every 600 mi

2 items

Check chain slack and rear wheel alignment

Pre-ride / on the road

Guideline
Lubricate drive chain

Pre-ride / on the road

Factory

Manual: Drive chain (check slack, alignment; adjust and lubricate). Factory: Every 1000 km (600 mi) and after washing or riding in rain

Every 1,000 mi or 6 months

1 item

Adjust front drum brake

Brakes

Guideline

Every 2,000 mi or 12 months

1 item

Replace spark plugs (two-stroke)

Engine

Guideline

Every 3,000 mi or 12 months

6 items

Check / set ignition timing

Ignition and electrics

Guideline
Clean and gap contact breaker points, oil cam felt

Ignition and electrics

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 footrests, pegs, rear brake and gear lever pivots

Rear suspension and frame

Guideline
Check spoke tension and wheel true

Wheels and tires

Guideline

Every 3,000 mi or 2 years

1 item

Decarbonize exhaust ports, pipes and baffles

Engine

Guideline

Two-strokes coke up the exhaust port and muffler baffles; power falls off gradually.

Every 3,500 mi or 12 months

11 items

Change engine oil

Engine

Factory

Manual: Engine oil (change, warm engine before draining). Factory: Cols 1000km(600mi) initial, then 6000km(3500mi) spacing to 24000km; annual check
Chassis fasteners (check tightness)

Engine

Factory

Factory: 6000km columns and annual check
Diagnostic system check (Yamaha diagnostic tool, error codes)

Engine

Factory

Factory: Every column incl. initial and annual check
Check throttle cable(s) free play and return

Fuel and air

Factory

Manual: Throttle grip housing and cable (check free play, lubricate). Factory: 6000km columns and annual check
Fuel injection (check and adjust engine idle speed)

Fuel and air

Factory

Factory: Every column incl. 1000km initial and annual check
Grease and check center / side stand and springs

Rear suspension and frame

Factory

Manual: Sidestand, centerstand (check operation, lubricate). Factory: 6000km columns and annual check
Adjust rear drum brake and rod / cable linkage

Brakes

Factory

Manual: Rear brake (check operation, adjust pedal free play; shoes). Factory: Every column incl. initial and annual check
Check brake pads and discs

Brakes

Factory

Manual: Front brake (check operation, fluid level, leakage; pads). Factory: Every column incl. initial and annual check
Unified brake system (check cable free play, lubricate pedal link pivot)

Brakes

Factory

Factory: 6000km columns and annual check
Inspect tire tread, sidewalls and date codes

Wheels and tires

Factory

Manual: Tires (check tread depth, damage, pressure). Factory: 6000km columns and annual check
Lubricate control cables and lever pivots

Controls and cables

Factory

Manual: Moving parts and cables; lever and pedal pivots (lubricate). Factory: 6000km columns and annual check

Every 3,500 mi

9 items

Check and adjust valve clearances

Engine

Factory

Manual: Valve clearance (check and adjust). Factory: 6000km(3500mi) columns; from 30000km repeat from 6000km
Exhaust system (check for leakage, tighten, replace gasket)

Engine

Factory

Factory: Marked 1000km initial, then every 6000km
Air filter case check hose (clean)

Fuel and air

Factory

Factory: Marked 1000km initial, then every 6000km
Adjust clutch free play, lubricate cable and lever pivot

Primary and gearbox

Factory

Manual: Clutch (check operation, adjust). Factory: Marked 1000km initial, then every 6000km
Check steering head bearing adjustment

Front end

Factory

Manual: Steering bearings (check bearing assemblies for looseness). Factory: Marked 1000km, 6000km, 12000km, 18000km
Inspect fork seals, stanchions and fork boots

Front end

Factory

Manual: Front fork (check operation and oil leakage). Factory: 6000km columns
Check swingarm bushes for play

Rear suspension and frame

Factory

Manual: Swingarm pivot bushes (check for looseness). Factory: 6000km columns
Inspect rear shocks for leaks and damping

Rear suspension and frame

Factory

Manual: Shock absorber assemblies (check operation and oil leakage). Factory: 6000km columns
Check wheel bearings for play

Wheels and tires

Factory

Manual: Wheel bearings (check looseness or damage). Factory: 6000km columns

Every 4,000 mi or 12 months

1 item

Lubricate brake cam spindles, check linings and drums

Brakes

Guideline

Every 6,000 mi or 12 months

2 items

Check charging voltage and regulator / cut-out

Ignition and electrics

Guideline
Lubricate speedometer / tachometer cables, check drive

Controls and cables

Guideline

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

Every 6,000 mi or 2 years

2 items

Lubricate and check automatic advance unit

Ignition and electrics

Guideline
Magneto: clean slip ring and pickup brush, check HT lead

Ignition and electrics

Guideline

Every 7,000 mi

6 items

Inspect, clean and gap spark plugs

Engine

Factory

Manual: Spark plug (check condition, adjust gap and clean). Factory: Marked at 6000km and 18000km
Replace oil filter

Engine

Factory

Manual: Engine oil filter element (replace). Factory: Marked 1000km initial, 12000km, 24000km
Replace spark plugs

Engine

Factory

Manual: Spark plug (replace). Factory: Marked at 12000km and 24000km
Clean / inspect air filter

Fuel and air

Factory

Manual: Air filter element (clean). Factory: Clean at 6000km and 18000km
Replace air filter element

Fuel and air

Factory

Manual: Air filter element (replace). Factory: Marked at 12000km and 24000km
Grease swingarm pivot

Rear suspension and frame

Factory

Manual: Swingarm pivot bushes (lubricate, lithium-soap grease). Factory: Marked at 12000km and 24000km

Every 10,000 mi or 2 years

2 items

Compression test (or leak-down)

Engine

Guideline
Change gearbox oil

Primary and gearbox

Guideline

Every 12,000 mi or 2 years

1 item

Synchronize throttle bodies

Fuel and air

Guideline

Every 12,000 mi or 3 years

1 item

Replace points and condenser

Ignition and electrics

Guideline

Every 14,000 mi

1 item

Repack / replace steering head bearings

Front end

Factory

Manual: Steering bearings (moderately repack, lithium-soap grease). Factory: Marked at 24000km (14000mi)

Every 15,000 mi 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 15,000 mi

1 item

Replace brake linings / skim drums (wear based)

Brakes

Guideline

Every 18,000 mi

1 item

Replace chain and sprockets (wear based)

Final drive

Guideline

Every 20,000 mi or 4 years

1 item

Repack / replace wheel bearings

Wheels and tires

Guideline

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

Every 24,000 mi or 4 years

1 item

Replace fuel filter

Fuel and air

Guideline

Every 25,000 mi or 6 years

1 item

Replace swingarm bushes / bearings

Rear suspension and frame

Guideline

Every 25,000 mi or 10 years

1 item

Magneto overhaul / re-magnetize, replace capacitor

Ignition and electrics

Guideline

Weak spark when hot is the classic symptom. Old capacitors fail with age, not miles.

Every 30,000 mi 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
Rebuild calipers and master cylinders (seals)

Brakes

Factory

Manual: Brake master cylinder and caliper internal components (replace). Factory: Every two years (TIP under chart)
Replace brake fluid

Brakes

Factory

Manual: Brake fluid (change). Factory: Every 2 years

Every 4 years

2 items

Replace fuel lines

Fuel and air

Guideline

Old rubber and modern ethanol fuel do not mix well.
Inspect brake hoses; replace old rubber

Brakes

Factory

Manual: Brake hose (replace). Factory: Every 4 years; checked every 6000km and annually

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.