Stihl FS 85 User Manual

2.1 Engine STIHLsingle-cylindertwo-strokeenginewithspecialimpregnatedcylinder
bore
Displacement: 25.4ccm
Bore: 34mm
Pistonstroke: 28mm
PoweroutputtoISO8893: 0.9kW(1.2HP)at8000rpm
Max.permissibleenginespeed
withoutcuttingblades(cut-offspeed):10500rpm(
+000rpm)
Max.speedoftheoutputshaft
(nominalvalue,gearhead): 8500rpm(FS75,FC75)
7500rpm(FS80,85)
Idlespeed: 2800rpm
Bearings: Heavy-dutydeepgrooveball
bearingsforcrankshaft;needle
cagesonsmallandbigends
Bigenddiameter: 8mm
Conrodlength: 52.5mm
Rewindstarter: ElastoStart
Pawls: Singlepawlsystem
Reservepullonroperotor: Atleastturn
Starterrope: Dia.3.0mm,800mmlong
Clutch: Centrifugalclutchwithoutlinings
Diameter: 66.5mm
Clutchengagesat: 3700rpm
Crankcaseleakagetest
atgaugepressure: 0.5bar
undervacuum: 0.5bar
2.2 Fuelsystem Carburetor: Diaphragmcarburetorwithoneor
twoadjustingscrews
Standardsettingforcarburetors
withtwoadjustingscrews
HighspeedadjustingscrewH: Backoffapprox.1turn
LowspeedadjustingscrewL: Backoffapprox.1turn
(standardsetting)
Carburetorleakagetestatgauge
pressure: 0.8bar
Functionoftankvent
atgaugepressure: 0.5bar
undervacuum: 0.1bar
Fueltankcapacity: 0.44l(440ccm)
Octanenumber: Atleast90RON
Fuelmixture: Regularbrandnamepetrol
Brandnametwo-strokeengineoil
Mixratio: 1:50whenusingSTIHL1:50
two-strokeengineoil
1:25whenusingallotherbrand-
nametwo-strokeengineoils
Airfilter: Foamandfeltelements
2. Specifications
3

Stihl FS 85 Specifications

General

Engine Type	2-stroke
Displacement	25.4 cc
Weight	5.2 kg
Shaft Type	Straight
Starter	Recoil
Vibration Damping	Yes
Power Output	0.95 kW
Fuel Capacity	0.44 liters