Honda Metropolitan CHF50 User Manual

CRANKSHAFT/PISTON/CYLINDER
PISTON/CYLINDER INSPECTION
Inspect the piston rings for movement by rotating
the rings. The rings should be able to move in their
grooves without catching.
Push the ring until the outer surface of the piston
ring is nearly flush with the piston and measure the
ring-to-groove clearance.
SERVICE LIMIT:
Top: 0.08 mm (0.003 in)
Second: 0.08 mm (0.003 in)
Insert each piston ring into the bottom of the cylin-
der squarely using the piston.
Measure the ring end gap.
SERVICE LIMIT:
Top/Second: 0.40 mm (0.016 in)
Oil (side rail): 0.80 mm (0.031 in)
Measure the piston pin hole. Take the maximum
reading to determine I.D.
SERVICE LIMIT: 10.04 mm (0.395 in)
Measure the piston pin O.D. at piston and connect-
ing rod sliding areas.
SERVICE LIMIT: 9.98 mm (0.393 in)
Calculate the piston-to-piston pin clearance.
SERVICE LIMIT: 0.04 mm (0.002 in)
Measure the connecting rod small end I.D.
SERVICE LIMIT: 10.05 mm (0.396 in)
Calculate the connecting rod-to-piston pin clear-
ance.
SERVICE LIMIT: 0.06 mm (0.002 in)
12-8

Honda Metropolitan CHF50 Specifications

General

Engine Type	49cc liquid-cooled single-cylinder four-stroke
Ignition	CDI
Transmission	Automatic V-Matic belt drive
Rear Suspension	Single shock
Front Brake	Drum
Rear Brake	Drum
Front Tire	80/100-10
Rear Tire	80/100-10
Seat Height	28.3 inches
Fuel Capacity	1.3 gallons
Bore x Stroke	37.8mm x 44.0mm
Compression Ratio	12.0:1
Starter	Electric
Curb Weight	179 pounds