1 SERVICE INFORMATION
1-1 Speci
fi
cations
Dimensions Length
mm(in)
448 (17.64)
Width
mm(in)
253
(9.96)
Height
mm(in)
284
(11.18)
Dry weight*
kg(lb)
6.0 (13.2)
Engine Type
YAMABIKO, strati
fi
ed scavenging, air-cooled, two-stroke,
single cylinder Ventilated piston, Semi-automatic decompression
Rotation
Clockwise as viewed from the output end
Displacement
cm
3
(in
3
) 54.1
(3.301)
Bore
mm(in)
45.0
(1.772)
Stroke
mm(in)
34.0
(1.339)
Compression
ratio
7.2
Carburettor Type
Diaphragm
horizontal-draught
Model
Walbro WLA-4 with Large D-shaped mixture needles
Venturi size-Throttle bore mm(in)
13.49 - 15.85 (0.531 - 0.624)
Ignition
Type
CDI (Capacitor discharge ignition) system
Digital magneto
Spark
plug
BPMR8Y
Exhaust
Muf
fl
er type
Spark arrester muf
fl
er
Starter Type
Automatic
rewind
Rope diameter x length
mm(in)
4.0 x 950 (0.15 x 37.4)
Fuel
Type
Premixed two-stroke fuel
Mixture
ratio
50 : 1 (2 %)
Petrol
Minimum 89 octane petrol
Two-stroke air cooled engine oil
ISO-L-EGD (ISO/CD13738), JASO FC/FD
Tank capacity
L (U.S.
fl
.oz.)
0.53 (17.9)
Clutch Type
Inboard clutch : Centrifugal, 3-shoe slide with 3-tension spring
Guide bar / Saw chain lubrication type
Automatic with volume adjuster
Tank capacity, oil
L (U.S.
fl
.oz.)
0.3 (10.1)
Sprocket Type
Floating
rim
Number of teeth
7
Pitch
in
0.325,
3/8
* Without guide bar and saw chain.
Oregon Saw chain 21BPX
Cutting devices
Guide bar
Part No.
38RV58-325E
45RV58-325E
50RV58-325E
Called length
cm
38
45
50
Gauge
in
0.058
Saw chain
Number of drive links
64
72
80
Pitch
in
0.325
Gauge
in
0.058
SERVICE INFORMATION
CS-550
2