Honda CB 250 G (1974–1977) — Specs
Identity
Manufacturer: Honda
Model: CB 250 G
Category: Motorcycle
Type: Motorcycle
Years: 1974 → 1977
Engine
Displacement (cc): 249
Cylinders: 2
Power (hp): 27
Power (kW): 20
Torque (Nm): 22
Dimensions
Overall length: 2070 mm
Overall width: 770 mm
Overall height: 1130 mm
Wheelbase: 1395 mm
Ground clearance: 155 mm
Weight (kg): 175
Seat height (mm): 840
Tank (L): 11
Tires
Front tire: 100/90-18
Rear tire: 110/90-18
Front pressure (bar): 1.8
Rear pressure (bar): 2.5
Drivetrain
Drive chain: 428 chain, 96 links
Sprockets (front / rear): 16 / 38
Ignition
Spark plug: NGK B8ES
Plug gap: 0.7-0.8 mm
Fluids & Filters
Engine oil: SAE20W-40, 10W-30
Engine oil (with filter, L): 2
Oil filter: Hiflofiltro HF112
Air filter: Hiflofiltro HFA1210
Brake fluid: DOT 4
Fuel consumption
Estimated range: ~366 km on a full tank (11.0 L)
Service
Battery: OEM battery specification
Service interval (km): 10000
Service interval (months): 12
Valve check (km): 24000
Parts and consumables for this motorcycle
Data is gathered with care, but without guarantee. Always confirm critical information with your dealer or workshop.
Service notes
Service interval: every 10,000 km or 12 months, whichever comes first. Valve clearance check every 24,000 km. Valve clearance — intake cold: 0.05 mm, exhaust cold: 0.10 mm. Engine oil: oil grade SAE20W-40, 10W-30, 2 L with filter change. Spark plug: NGK B8ES (gap 0.7-0.8 mm). Brake fluid: DOT 4. Chain: 96 links, sprockets 16/38 teeth. Tire pressure: front 1.8 bar, rear 2.5 bar (cold). Tire size: front 100/90-18, rear 110/90-18. Always confirm critical values with the workshop manual or an authorised dealer.
OEM and quality aftermarket parts that fit this bike. Always confirm with your dealer before ordering.
Engine oil
Spec: SAE20W-40, 10W-30, 2.0 L (with filter)
- OEM OEM recommended engine oil (SAE 20W-40)
- Premium Motul 7100 4T (100% Synthetic, Ester)
- Premium Motul 5100 4T Technosynthese (Semi-Synthetic)
Which Motul for this bike?
| Motul 7100 4T ✓ | Motul 5100 4T | |
|---|---|---|
| Product | Motul 7100 4T — 100% fully synthetic | Motul 5100 4T — semi-synthetic |
| Best for | Sport, Naked, Adventure (600cc+), track | Standard, Cruiser, Scooter, daily use |
| RPM protection | Excellent — ester base, stable under load | Good — for normal riding conditions |
- Standard Repsol Moto Racing 4T (Synthetic)
- Standard Elf Moto 4 Tech (Semi-Synthetic)
Fully Synthetic vs Semi-Synthetic
| Fully Synthetic | Semi-Synthetic | |
|---|---|---|
| Base oil | 100% chemical synthesis (ester or PAO) | Mineral oil + synthetic additives |
| Heat resistance | Excellent — stable at extreme heat & RPM | Good — suitable for normal temperatures |
| Cold start | Better — reaches engine faster when cold | Good — adequate for normal climates |
| Change interval | Longer (up to 10,000 km) | Shorter (5,000–7,000 km typical) |
| Price | Higher | Lower |
Oil filter
Spec: Hiflofiltro HF112
- Premium Hiflofiltro HF112
- Premium K&N KN-112
Air filter
Spec: Hiflofiltro HFA1210
- Standard Hiflofiltro HFA1210
Spark plug
Spec: NGK B8ES, gap 0.7-0.8 mm
- OEM NGK B8ES
- Premium NGK B8ESIX
- Standard NGK B8ES
Front brake pads
Rear brake pads
Drive chain
Spec: 96 links | Sprockets 16/38 teeth / 96 links
- OEM OEM chain (pitch 520 (or 428 for some commuter 250s))
Front tire
Spec: 100/90-18, 1.8 bar
- OEM OEM 100/90-18
Rear tire
Spec: 110/90-18, 2.5 bar
- OEM OEM 110/90-18
Battery
- Premium Yuasa YTX7L-BS or YTX7A-BS (typical 125-250cc)
Brake fluid
Spec: DOT 4
- Standard TotalEnergies HBF4
Coolant
Service interval
Spec: 10 000 km / 12 months
- OEM Engine oil + oil filter change
- OEM Air filter inspection
- OEM Spark plug check
- OEM Brake fluid replacement: every 2 years
Valve check
Spec: 24 000 km
- OEM Intake clearance: cold: 0.05 mm
- OEM Exhaust clearance: cold: 0.10 mm
Suspension
Spec: telescopic fork / 180-190 ml
- OEM Fork: telescopic fork
- OEM Fork oil grade: 180-190 ml
