Sym Citycom 300i Service Manual

6. Cylinder Head / Valve
6-12
Use 60ƒ cutter to cut a quarter lower parts out.
Remove the cutter and check new valve seat.
Use 45ƒ cutter to grind the valve seat to specified
width.
Caution

Make sure that all roughness and uneven faces
had been ground.
Grind valve seat again if necessary.
Coat the valve seat surface with red paint.
Install the valve through valve guide until the valve
contacting with valve seat, slightly press down the
valve but do not rotate it so that a seal track will be
created on contact surface.
Caution
 The contact surfaces of valve and valve seat
are very important to the valve sealing capacity.
If the contact surface is too high, grind the valve
seat with 32ƒ cutter.
Then, grind the valve seat to specified width.
If the contact surface too low, grind the valve seat
with 60ƒ cutter.
Then, grind the valve seat to specified width.
Old valve seat width
60‚
1.0mm
60‚
45‚
32‚
Old valve seat width
Contact surface too high
Old valve seat width
Contact surface too low
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Sym Citycom 300i Specifications

General

Engine Type	4-stroke, Single Cylinder
Displacement	278.3 cc
Fuel System	Electronic Fuel Injection
Cooling System	Liquid Cooled
Front Suspension	Telescopic Fork
Rear Suspension	Dual Shock Absorbers
Front Tire	110/70-16
Rear Tire	140/70-16
Seat Height	800 mm
Transmission	CVT
Front Brake	Disc
Rear Brake	Disc
Fuel Capacity	10 liters