STIHL single-cylinder two-stroke engine with special impregnated cylinder
bore
Displacement:
25.4 ccm
Bore:
34 mm
Piston stroke:
28 mm
Power output to ISO 8893:
0.9 kW (1.2 HP) at 8000 rpm
Max. permissible engine speed
without cutting blades (cut-off speed): 10500 rpm (+ 000 rpm)
Max. speed of the output shaft
(nominal value, gear head):
8500 rpm (FS 75, FC 75)
7500 rpm (FS 80, 85)
Idle speed:
2800 rpm
Bearings:
Heavy-duty deep groove ball
bearings for crankshaft; needle
cages on small and big ends
Big end diameter:
8 mm
Conrod length:
52.5 mm
Rewind starter:
ElastoStart
Pawls:
Single pawl system
Reserve pull on rope rotor:
At least turn
Starter rope:
Dia. 3.0 mm, 800 mm long
Clutch:
Centrifugal clutch without linings
Diameter:
66.5 mm
Clutch engages at:
3700 rpm
Crankcase leakage test
at gauge pressure:
0.5 bar
under vacuum:
0.5 bar
Carburetor:
Diaphragm carburetor with one or
two adjusting screws
Standard setting for carburetors
with two adjusting screws
High speed adjusting screw H:
Back off approx. 1 turn
Low speed adjusting screw L:
Back off approx. 1 turn
(standard setting)
Carburetor leakage test at gauge
pressure:
0.8 bar
Function of tank vent
at gauge pressure:
0.5 bar
under vacuum:
0.1 bar
Fuel tank capacity:
0.44 l (440 ccm)
Octane number:
At least 90 RON
Fuel mixture:
Regular brandname petrol
Brandname two-stroke engine oil
Mix ratio:
1:50 when using STIHL 1:50
two-stroke engine oil
1:25 when using all other brand-
name two-stroke engine oils
Air filter:
Foam and felt elements
3