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Chainsaw

Stihl MS 291

2-Stroke

The Stihl MS 291 is a 55.5cc 2-stroke Farm Boss chainsaw and the larger counterpart to the MS 271, accepting 18" to 20" guide bars. It delivers substantially more torque for bucking large hardwood and felling medium to large trees. The MS 291 runs a Zama carburetor and is built for hard agricultural and land-clearing use. Under heavy production cycles, the Zama carb diaphragm, fuel filter, and primer bulb require attention every 50–100 hours. Bar and chain health are critical at this displacement.

Verify before ordering: Fitment can vary by serial number, production date, region, and sub-model. Match the OEM number and physical dimensions before ordering.

Stihl MS 291 quick specs

Equipment
Chainsaw · 2-Stroke
Covered Parts
Spark Plug, Air Filter, Fuel Filter, Carburetor, Recoil Starter, Ignition Coil, Primer Bulb, Fuel Line Kit, Chain, Guide Bar
OEM References
0000 400 7000, 1141 120 1600, 0000 350 3518, 1141 120 0612, 1141 080 1801, 1141 400 1300, 4238 350 6201, 1141 358 7708
Model Family
MS 261, MS 271, MS 291
Data Confidence
Not yet independently reviewed

Quick Fitment

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Tune-Up Kit

Common service bundle: spark plug, air filter, fuel filter, carburetor, primer bulb, fuel line kit.

Maintenance Interval

Inspect filters and fuel lines each season, replace spark plugs during annual service, and service carb/fuel-system parts when starting or idle symptoms appear.

Before You Buy

  • Confirm the full model is Stihl MS 291, not just the family name.
  • Check serial number, production date, and regional variant before ordering.
  • Match the old OEM number stamped on the removed part when available.
  • Compare dimensions, plug gap, thread, fuel line diameter, or chain pitch/gauge where applicable.

Common Mistakes

  • Ordering from a family listing without checking the exact sub-model.
  • Buying a kit that includes the headline part but wrong gaskets, lines, or bulb size.
  • Choosing the wrong carburetor revision when multiple versions were used.
  • Assuming all fuel line kits use the same diameter and routing.
  • Installing the correct plug number with the wrong gap.
  • Matching bar length but missing pitch, gauge, or drive-link count.

Symptoms Map

Won't start

Spark plug, fuel filter, primer bulb, carburetor

Starts then dies

Fuel filter, fuel line kit, carburetor

Bogs under throttle

Air filter, carburetor, spark plug gap

Primer will not fill

Primer bulb, fuel line routing, in-tank filter

Cuts slowly

Chain pitch/gauge, bar wear, drive links

Replacement Options

Best OEM equivalent

Start with OEM references 0000 400 7000, 1141 120 1600, 0000 350 3518, 1141 120 0612 and match the removed part before choosing a listing.

Named part options

Cross-check named parts such as NGK BPMR7A (spark plug), Stens 605-205 (air filter), Walbro HDA-226 (carburetor) against the OEM number, identity label, and dimensions.

Best for annual tune-up

Bundle spark plug, air filter, fuel filter when servicing the Stihl MS 291 at the start of the season.

Best if replacing fuel system

Compare the fuel filter, carburetor, primer bulb, fuel line kit together so line routing, bulb size, filter style, and carburetor connections match.

Best chain/bar combo

Match chain specs together, especially pitch, gauge, drive links, and bar mount details.

Best budget kit

Use kit listings only when every included part matches this model page; cheap kits often mix correct headline parts with wrong bulbs, lines, or gaskets.

FAQ

Should I buy OEM or aftermarket parts for the Stihl MS 291? Use OEM when the part controls fuel metering, ignition, or safety. Aftermarket kits can be useful for routine filters, bulbs, plugs, and tune-up bundles when the OEM number and dimensions match.

How do I avoid ordering the wrong carburetor for the MS 291? Match the carburetor number stamped on the removed unit, then compare linkage, choke setup, primer routing, gasket stack, and fuel-inlet direction.

What should I check before replacing fuel-system parts? Photograph the old fuel-line routing, match line diameter and filter style, and compare primer bulb size before buying a kit.

What chain details matter besides bar length? Match pitch, gauge, and drive-link count against the bar stamp, old chain, and drive sprocket. Bar length alone is not enough.

As an Amazon Associate, WhichPartFits earns from qualifying purchases. Match the OEM number, dimensions, and model variant before buying.

Spark Plug

OEM0000 400 7000
Dimensions
0.5mm gap

Air Filter

OEM1141 120 1600
Variant notes
Fleece filter; HD2 style 1141 140 4400 also fits

Fuel Filter

OEM0000 350 3518
Variant notes
Orange in-tank pickup body fuel filter
  • No named part listing is published for this part yet. Use the OEM reference and verify with a dealer or service manual before ordering.

Carburetor

OEM1141 120 0612
Variant notes
Walbro HDA-226; also fits MS 271

Recoil Starter

OEM1141 080 1801
Variant notes
Fits MS 261, MS 271, MS 291

Ignition Coil

OEM1141 400 1300
Variant notes
Fits MS 261, MS 271, MS 291

Primer Bulb

OEM4238 350 6201
Variant notes
Newer units (SN# 287332321+) use 0000 350 6202

Fuel Line Kit

OEM1141 358 7708
Variant notes
Includes fuel pickup line and return line; fits MS261, MS271, MS291

Chain

OEMSpec-based fitment
Dimensions
20", .325" pitch, .050" gauge, 81 drive links
Variant notes
Stock bar length; verify drive link count matches your bar

Guide Bar

OEMSpec-based fitment
Dimensions
20", .325" pitch, .050" gauge