Honda Metropolitan (CHF50) - Master Maintenance & Torque Guide

The Honda Metropolitan (CHF50) uses a liquid-cooled 49cc GET single-cylinder engine shared with the Honda Ruckus (NPS50). As with most 50cc scooters, maintaining precise fluid levels and torque specs prevents vacuum leaks and oil starvation.

⚡ Quick Maintenance Specs & Direct Answers

  • Engine Oil: SAE 10W-30 API SG/SL JASO MB
  • Engine Capacity: 0.6L (drain) / 0.7L (total)
  • Gear Oil & Volume: SAE 10W-30 / 80W-90 | 100ml (drain) / 120ml (total)
  • Oil Filter: Strainer Screen OEM # 15421-107-000
  • Air Filter: OEM # 17213-GET-000
  • Spark Plug: NGK CR6HSA (0.6-0.7mm gap)

Engine Fluids, Gear Oil & Filter Specifications

Specification Parameter OEM Factory Technical Value
Engine Oil Viscosity & Standard SAE 10W-30 | API SG/SL | JASO MB Standard
Engine Oil Drain & Refill Capacity 0.6L (without filter / drain) / 0.7L (total capacity)
Final Drive / Gearbox Oil & Capacity SAE 10W-30 / 80W-90 | 100ml (drain) / 120ml (total)
OEM Oil Filter Part Number Strainer Screen OEM # 15421-107-000 (Clean with solvent at drain interval)
OEM Air Filter Element Part Number OEM # 17213-GET-000 (Air cleaner element)
Spark Plug Model & Electrode Gap NGK CR6HSA | Electrode Gap: 0.6-0.7mm (0.024-0.028 in)
Expert Maintenance Note: Due to the compact 0.6L engine oil drain volume, changing oil at regular intervals using JASO MB certified 10W-30 fluid is essential. Inspect and clean the oil strainer screen (OEM # 15421-107-000) at every oil change. For shared platform information, consult the Honda Ruckus NPS50 Master Guide.

Engine Internals: Cylinder Head & Crankshaft

Cylinder Head Assembly (Air-Cooled SOHC)
Part No.QtyPart NameNotes
12100-GET-A211Head Comp., CylinderFinned aluminum, resurface flatness < 0.05mm
12210-GET-A211Valve, ExhaustCheck margin thickness > 0.5mm before reuse
12200-GET-A211Valve, InletDo not swap positions with exhaust valve
12251-GET-A211Gasket, Cylinder HeadSingle-use metal composite
14100-GET-A211Camshaft Comp.Chain-driven; inspect lobe wear before reinstall
Crankshaft & Piston Assembly
Part No.QtyPart NameNotes
13300-GET-A211Crankshaft Comp.Check runout < 0.03mm on V-blocks
13210-GET-A211Connecting RodBig-end side clearance spec: 0.1-0.4mm
13010-GET-A211Piston (Std.)Domed piston, 2-ring set
13111-GET-A211Piston PinLightly oil before install; hand-pressure fit only
13115-GET-A212Piston Pin Clip (Circlip)Directional installation — see expert note below
Field note: On this small-bore carbureted single, the piston pin circlips must be fitted with their opening gap 90° to the direction of piston travel, never fore-or-aft. A backward clip compresses under inertial load on every stroke until it walks out of its groove and ejects into the crankcase, and the freed pin gouges the cylinder wall on the following stroke. Always fit new clips only, and confirm full seating by feel before closing the case halves.

OEM Body Panels & Color Matching

Part NameOriginal WhiteOriginal SilverOriginal Blue
Front Leg ShieldConsult Service ManualConsult Service ManualConsult Service Manual
LH Side CoverConsult Service ManualConsult Service ManualConsult Service Manual
RH Side CoverConsult Service ManualConsult Service ManualConsult Service Manual
Rear FenderConsult Service ManualConsult Service ManualConsult Service Manual
Floor Board PanelConsult Service ManualConsult Service ManualConsult Service Manual
Field note: Given this platform's long production run, assume the plastic mounting tabs behind the painted surface are already past the typical three-year UV brittleness threshold on most surviving units. Never use an impact driver on body screws, and apply silicone grease to rubber grommets before removal — color-matched replacement panels for older production years are frequently discontinued.

Official Technical Reference

The specifications above are cross-checked wherever possible, but this guide does not replace the factory service manual. Before ordering parts or performing a repair, confirm current fitment and revision bulletins directly with Honda Powersports.

Visit Honda Powersports Official Site & Parts Resources