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Single cylinder four-stroke overhead valve engine
FS 25-4
FS 65-4
Type:
GX 22
GX 31
Displacement:
22 cm
3
31 cm
3
Bore:
33 mm
39 mm
Stroke:
26 mm
26 mm
Power output to ISO 8893:
0.6 kW (0.8 bhp)
0.85 kW (1.2 bhp)
at 7,000 rpm
at 7,000 rpm
Max. engine speed:
Maximum rpm is determined by main jet and is not adjustable
Idle speed:
3,100
±
200 rpm
Compression pressure:
29 - 59 kPa (2.9 - 5.9 bar)
at 1,200 rpm
Piston pin diameter:
8 mm
Rewind starter:
Pawl engagement
Pawls:
Single pawl system
Reserve pull on rope rotor:
min. 1/2 turn
Starter rope diameter:
3 mm
Clutch:
Centrifugal clutch with press-fitted linings
Clutch engages at:
4,200
±
200 rpm
Valve clearance
Inlet:
0.12
±
0.02 mm
Exhaust:
0.15
±
0.02 mm
Oil capacity:
0.1 l (100 cm
3
)
Oil grade:
SAE 15W-40
Carburetor:
Diaphragm carburetor
Carburetor leakage test
at gauge pressure:
8 kPa (0.8 bar)
Function of tank vent
at gauge pressure:
≤
3 kPa (0.3 bar)
under vacuum:
≤
0.5 kPa (0.05 bar)
Fuel tank capacity:
0.45 l (450 cm
3
)
0.65 l (650 cm
3
)
Fuel:
Regular brand name gasoline
Octane rating:
min. 90 RON
Air filter:
Oil impregnated foam filter
FS 25-4, 65-4
3