Stihl MS 291 Chainsaw Specifications
Stihl MS 291 Specifications for the Stihl MS291 chainsaw. Find detailed specs information for the Stihl chainsaw including engine, fuel system, Carburetor, ignition system, chain lubrication,Torque settings and cutting attachments.
Stihl MS 291 Chainsaw Specs
Stihl MS 291 Specifications Carburetor
Replace carburetor with Zama carb: Zama C1Q-S252, C1M-S246 and C1Q-S252
MS291 Engine
Displacement: 3.39 cu. in. (55.5 cm3)
Bore: 1.85 in. (47.0 mm)
Stroke: 1.26 in. (32 mm)
Power output to ISO 7293: 3.8 hp (2.8 kW) at 9,500 rpm
Max. permissible engine speed (with bar and chain): 13,000 rpm
Idle speed: 2,800 rpm
Clutch: Centrifugal clutch without linings
Clutch engages at: 3,600 rpm
Crankcase leakage test at gauge pressure: 0.5 bar (7.25 psi)
under vacuum: 0.5 bar (7.25 psi)
MS291 Fuel System
Carburetor: All position diaphragm carburetor with integral fuel pump
Carburetor leakage test at gauge pressure: 0.8 bar (11.6 psi)
Function of tank vent at gauge pressure: (±) (±) 0.05 bar (0.725 psi)
Fuel tank capacity: 16.9 fl.oz (0.50 l)
Octane rating: min. 90 RON (US/CAN; pump octane min. 87)
Fuel mixture: Regular brand name gasoline and two-stroke engine oil
Mix ratio: 50:1 with STIHL two-stroke engine oil, 25:1 with other brand name two-stroke, air-cooled engine oils
MS291 Ignition System
Type: Electronic magneto ignition
Air gap: 0.20 (+ 0.1/- 0.05) mm
Spark plug (suppressed): Bosch WSR 6 F or NGK BPMR 7 A
Electrode gap: 0.5 mm (0.020 in)
MS291 Chain Lubrication
Chain lubrication: Speed-controlled oil pump with reciprocating piston
Oil deivery rate: approx. 8.0 (+/2.0) cm3/min at 10,000 rpm
Oil tank capacity: 8.1 fl.oz (0.24 l)
MS291 Weight
Dry, without cutting attachment: 12.3 lbs. (5.6 kg)
MS291 Cutting attachments
Rollomatic E guide bars
Reduced kickback STIHL guide bars (with green label)
Bar lengths: 40, 45, 50 cm (16, 18, 20 in.)
Pitch: .325″ (8.25 mm)
Groove width: 1.6 mm (0.063 in.)
Sprocket nose: 11-tooth
Saw chain .325″
Low kickback STIHL saw chain (with green label)
Rapid Micro 3 (26 RM3) Type 3634
Pitch: .325″ (8.25 mm)
Drive link gauge: 1.6 mm (0.063 in)
Chain sprocket
7-tooth for .325″ (spur sprocket)
Replace spark plug with Bosch WSR 6 F or NGK BPMR 7 A
Stihl MS 291 Specifications Tightening Torques
DG screws are used in the polymer and light-alloy components. These screws form a permanent thread
when they are installed for the first time. They can be removed and installed as often as necessary without
detrimentally affecting the strength of the screwed assembly, providing the specified tightening torque is
observed. For this reason it is essential to use a torque wrench when using the MS 291 Specifications.
More Stihl MS 291 Specifications information can be found in Carburetor Manuals HERE and a Stihl MS291 chainsaw workshop manual HERE. Stihl Parts list HERE a chainsaw search (magnifier icon) at top and bottom of this page, as well as a chainsaw repair help question and answer page HERE.