1-2 Technical data
Engine
Idling speed
r/min
2,800 +/- 200
Wide open throttle speed*
r/min
12,500 - 13,500
Clutch engagement speed
r/min
4,000
Minimum
†
r/min
3,300
Compression pressure
MPa (kgf/cm
2
) (psi)
1.04 (10.6) (151)
Ignition system
Spark plug gap
mm(in)
0.6 - 0.7 (0.024 - 0.028)
Minimum secondary voltage at 1,500 r/min
kV
17
Primary coil resistance
Ω
300 - 340
Secondary coil resistance
k
Ω
2.5 - 2.9
Pole shoe air gaps
mm (in)
0.30 - 0.40 (0.012 - 0.016)
Ignition timing
at 3,000 r/min
°BTDC
5
at 8,000 r/min
°BTDC
24
at 12,000 r/min
°BTDC
28
PET-9000
Parameter
1
325
Parameter
2
03
Carburettor
Idle adjust screw initial setting
turns in**
1 3/8
L mixture needle initial setting
turns out***
1 3/8
H mixture needle initial setting
turns out***
3 3/8
Test Pressure, minimum
MPa (kgf/cm
2
) (psi)
0.05 (0.5) (7.0)
Metering lever height
mm(in)
1.50 (0.06) lower than diaphragm seat
Chain oil discharge volume at 7,000 r/min
Adjustable 1.5 - 13 (0.05 - 0.39)
mL/min(U.S.
fl
.oz./min)
(Factory set 7.0 mL/min)
BTDC: Before top dead center.
*With 50 cm guide bar and properly adjusted saw chain.
**Set idle adjust screw to the point that its tip just contacts throttle plate before initial setting.
***Turn L/H mixture needles anticlockwise from point that needle is lightly seated.
†
If clutch engagement speed is lower than minimum r/min, replace clutch assembly with new one.
Oregon Saw chain 73LGX
Cutting devices
Guide bar
Part No.
40RV58-3/8E
45RV58-3/8E
50RV58-3/8E
Called length
cm
40
45
50
Gauge
in
0.058
Saw chain
Number of drive links
60
64
72
Pitch
in
3/8
Gauge
in
0.058
SERVICE INFORMATION
CS-550
3