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Hero · Overhead-cam four-stroke single, wet sump, separate gearbox oil, CVT belt drive

Duet (111 cc)

Library entry covers 2015-2020

41 factory 48 guideline

Published source

Hero DUET Owner's Manual, Maintenance schedule pp.49-51 (ManualsLib 2320180)

Factory source. Covers Hero DUET owner's manual (vehicle identification page prints Model: DUET, VX and LX; no year or edition printed in the pages read).

89 items for a 2015 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: Separate gearbox oil
Clutch control: Automatic or semi-automatic
Final drive: Belt CVT, scooter automatic
Front suspension: Telescopic fork
Rear suspension: Swingarm, single shock / cantilever
Front brake: Disc, hydraulic
Rear brake: Drum (or band / belt rim)
Wheels: Cast / alloy, tubeless
Sidecar: No sidecar

Maintenance schedule

2015 Hero Duet (111 cc)

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

2 items

Check lights, horn, brake light switches

Pre-ride / on the road

Guideline
Check tire pressures

Pre-ride / on the road

Guideline

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

29 items

Belt case and kick starter driven gear (clean, lubricate)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Bystarter operation (inspect, adjust)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Drain and crankcase breather tube (inspect, clean)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km; more often in rain or at full throttle (note 4). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Engine oil (top up)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): after the free services, every 3,000 km if the level is at or near the lower mark. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Front suspension (inspect)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Headlamp focus (inspect)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Nuts, bolts and fasteners (inspect)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Parking lock operation (inspect)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Pivot arm (lubricate; LX model)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Rear suspension mounting bushes (inspect for play, replace if necessary)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Spark plug (inspect, clean, adjust)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): I, C, A at the 1st to 4th free services, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Stop lamp switch (inspect)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Throttle operation (inspect, adjust)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Valve clearance (inspect, adjust)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Air cleaner element (inspect)

Fuel and air

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): I at the 2nd to 4th free services and every 3,000 km; at 12,000 km inspect whether it is choked and replace if so (note 3). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Engine idle speed and carburetor (inspect, adjust; clean carburetor if required)

Fuel and air

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Fuel lines (inspect)

Fuel and air

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Fuel tank lid cover operation (inspect, adjust)

Fuel and air

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Secondary air cleaner element (clean)

Fuel and air

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km; more often in wet or dusty areas (note 9). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Battery voltage (check)

Ignition and electrics

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Steering head bearings (inspect, adjust)

Front end

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): I, A at the 1st to 4th free services, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Main stand (lubricate)

Rear suspension and frame

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Side stand switch, if fitted (inspect, clean)

Rear suspension and frame

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Side stand, optional (lubricate)

Rear suspension and frame

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Brake shoe wear (inspect)

Brakes

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Brake system (clean, lubricate)

Brakes

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Front / integrated brake lever free play (inspect, adjust)

Brakes

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Wheel bearings (inspect free play, replace if necessary)

Wheels and tires

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Wheels and tires (inspect)

Wheels and tires

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at every free service, then every 3,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.

Every 5,000 km or 12 months

9 items

Check throttle cable(s) free play and return

Fuel and air

Guideline
Clean fuel tap filter / sediment bowl

Fuel and air

Guideline
Adjust automatic / semi-automatic clutch

Primary and gearbox

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 wheel bearings for play

Wheels and tires

Guideline

Every 6,000 km

6 items

Drive belt (inspect)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at the 3rd and 5th free services, then every 6,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Engine oil (replace)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): R at the 1st, 3rd and 5th free services (top up at the 2nd and 4th), then once in every 6,000 km (note 6). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Engine oil strainer screen (clean)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): C at the 1st, 3rd and 5th free services, then every 6,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Muffler and catalytic converter (inspect; idle CO emission check)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at the 3rd and 5th free services, then every 6,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Secondary air injection system (inspect)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at the 3rd and 5th free services, then every 6,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Clutch shoe wear (inspect)

Primary and gearbox

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at the 3rd and 5th free services, then every 6,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.

Every 6,500 km or 12 months

3 items

Inspect, clean and gap spark plugs

Engine

Guideline
Inspect CVT drive belt, rollers / sliders and clutch shoes

Final drive

Guideline

Typical scooter interval. Your owner's manual figure governs; check belt width against the service limit.
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 or 12 months

1 item

Final drive oil (replace)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): R at the 4th free service, then once in every 10,000 km or once a year, whichever is earlier (note 7). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.

Every 12,000 km

2 items

Spark plug (replace)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at the 5th free service, then once in every 12,000 km (note 5). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Steering head bearings (lubricate)

Front end

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): at the 5th free service, then every 12,000 km. Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.

Every 13,000 km or 2 years

1 item

Check and adjust valve clearances

Engine

Guideline

Every 15,000 km

1 item

Air cleaner element (replace)

Fuel and air

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): once in every 15,000 km; earlier in dusty areas (note 3). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.

Every 16,000 km or 2 years

2 items

Compression test (or leak-down)

Engine

Guideline
Change gearbox oil

Primary and gearbox

Guideline

Every 19,500 km or 2 years

3 items

Replace air filter element

Fuel and air

Guideline
Clean and grease rear suspension linkage

Rear suspension and frame

Guideline
Grease swingarm pivot

Rear suspension and frame

Guideline

Every 19,500 km or 3 years

1 item

Replace CVT drive belt

Final drive

Guideline

Typical scooter interval, or sooner if the belt is cracked, glazed or below its width limit.

Every 20,000 km or 2 years

1 item

Front fork oil (replace)

Front end

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): once in every 2 years or 20,000 km, whichever is earlier (note 14). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.

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

2 items

Drive belt (replace)

Engine

Factory

Factory: Maintenance schedule (Hero DUET owner's manual, printed pp.49-51, ManualsLib viewer pp.52-54): once in every 24,000 km (note 12). Free service columns as printed: 1st 500-750 km or 60 days; 2nd 3,000-3,500 km; 3rd 6,000-6,500 km; 4th 9,000-9,500 km; 5th 12,000-12,500 km (each within the next 100 days). After the free services: once in every 3,000 / 6,000 / 9,000 / 12,000 / 15,000 km. Each paid service within 90 days or 3,000 km of the previous one, whichever is earlier; at higher odometer readings repeat the established frequency (note 1). Key: I inspect; C clean; E emission check; R replace; A adjust; L lubricate; T top up.
Replace brake linings / skim drums (wear based)

Brakes

Guideline

Every 25,500 km or 4 years

1 item

Replace spark plugs

Engine

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

3 items

Inspect wiring, bullet connectors and ground points

Ignition and electrics

Guideline
Inspect frame, welds and lugs for cracks

Rear suspension and frame

Guideline
Replace brake fluid

Brakes

Guideline

Every 4 years

3 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

Guideline
Rebuild calipers and master cylinders (seals)

Brakes

Guideline

Every 6 years

1 item

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.