Instruction Manual

MS 231, MS 231 C, MS 251, MS 251 C
English
48
EPA / CEPA
The Emission Compliance Period
referred to on the Emissions
Compliance Label indicates the number
of operating hours for which the engine
has been shown to meet Federal
emission requirements.
Category
Engine
STIHL single cylinder two-stroke engine
MS 231
MS 251, MS 251 C
Ignition System
Electronic magneto ignition
This spark ignition system meets all
requirements of the Canadian
Interference-Causing Equipment
Standard CAN ICES-2/NMB-2.
Fuel System
All position diaphragm carburetor with
integral fuel pump
Chain Lubrication
Fully automatic, speed-controlled oil
pump with rotary piston
Weight
Cutting Attachment
Actual cutting length may be less than
the specified length
STIHL cutting attachments complying
with CSA Standard Z 62.3:
.325" Rollomatic E guide bars
3/8" P Rollomatic E guide bars
.325" chain
3/8" P chain
Chain sprocket
Specifications
A = 300 hours
B = 125 hours
C = 50 hours
Displacement: 42.6 cc
Bore: 42.5 mm
Stroke: 30 mm
Engine power to
ISO 7293:
2.0 kW (2.7 bhp)
at 10,000 rpm
Idle speed:
1)
2,800 rpm
Displacement: 45.6 cc
Bore: 44 mm
Stroke: 30 mm
Engine power to
ISO 7293:
2.2 kW (3.0 bhp)
at 10,000 rpm
Idle speed:
1)
1)
to ISO 11681 +/- 50 rpm
2,800 rpm
Spark plug (resistor
type):
NGK CMR6H,
BOSCH USR 4 A
C
Electrode gap: 0.5 mm
Fuel tank capacity: 390 cc (0.39 l)
Oil tank capacity: 200 cc (0.2 l)
dry, without bar and chain
MS 231: 4.9 kg
MS 251: 4.9 kg
MS 251 C with ErgoStart and
quick chain tensioner: 5.2 kg
Cutting lengths: 35, 40, 45 cm
Pitch: .325" (8.25 mm)
Groove width: 1.6 mm
Nose sprocket: 11-tooth
Cutting lengths: 30, 35, 40, 45 cm
Pitch: 3/8" P (9.32 mm)
Groove width: 1.3 mm
Nose sprocket: 9-tooth
Rapid Micro 3 (26 RM3) Type 3634
Rapid Duro 3 (26 RD3) Type 3667
Pitch: .325" (8.25 mm)
Drive link gauge: 1.6 mm
Picco Micro 3 (63 PM3) Type 3636
Picco Super 3 (63 PS3) Type 3616
Picco Duro 3 (63 PD3) Type 3612
Pitch: 3/8" P (9.32 mm)
Drive link gauge: 1.3 mm
7-tooth for .325"
6-tooth for 3/8" P
6-tooth for .325"