Stihl MS 311 Manual

5MS 311, MS 391
2. Specifications
2.1 Engine
MS 311 MS 391
Displacement: 59 cm
3
64.1 cm
3
Bore: 47 mm 49 mm
Stroke: 34 mm 34 mm
Engine power to ISO 7293: 3 kW (4 bhp)
at 9,500 rpm
3.2 kW (4.4 bhp)
at 9,500 rpm
Maximum permissible engine speed
with guide bar and chain: 13,000 rpm 13,000 rpm
Idle speed: 2,800 rpm 2,800 rpm
Clutch: Centrifugal clutch without
linings
Centrifugal clutch without
linings
Clutch engages at: 3,500 rpm 3,500 rpm
Engine housing leakage test
at gauge pressure: 0.5 bar
under vacuum: 0.5 bar
2.2 Fuel System
Carburetor leakage test at
gauge pressure:
0.8 bar
Operation of tank vent at
gauge pressure:
0.5 bar
Fuel: as specified in instruction
manual
2.3 Ignition System
Air gap between ignition
module and fanwheel: 0.20...0.30 mm
Spark plug (resistor type): NGK BPMR 7 A
BOSCH WSR6F
Electrode gap: 0.5 mm
2.4 Chain Lubrication
Speed-controlled oil pump with reciprocating piston and
manual flow control
Oil delivery rate:
Ematic oil pump
11.5 (+2.5) cm
3
/min
at 10,000 rpm
Oil delivery rate:
Adjustable oil pump
6.0 (+/-2.0)...17.5 (+3.0 / -4.5)
cm
3
/min at 10,000 rpm

Stihl MS 311 Specifications

General

Oil tank capacity	0.348 L
Fuel tank capacity	0.6 L
Power source	Gasoline

Weight and Dimensions

Weight	6200 g