Honda CB250 Nighthawk Owner's Manual page 178

Fuel & Lubricants
fuel
recommendation
fuel tank capacity
fuel tank reserve
engine oil capacity
engine oil
recommendation
drive chain
lubricant
unleaded gasoline, pump octane number of 86 or higher
4.23 US gal (16.0 )
0.85 US gal (3.2 )
after disassembly:
after draining: 1.6 US qt (1.5 )
API Service Classification SG or higher except oils
labeled as energy conserving on the circular API service
label, SAE 10W-40, JASO T 903 standard MA,
Pro Honda GN4 or HP4 (without molybdenum additives)
4-stroke oil , or an equivalent motorcycle oil
SAE 80 or 90 gear oil
including reserve
1.9 US qt (1.8 )
Technical Information
Specifications
169