Stihl model · engine series 1143

MS 251 45.6 cc

Chain: .325″ · .050–.063″
Recommended bar: 14–18″
Mount: 3005 / A074

Model displacement · family chain/bar fitment. Details & confidence ↓

Parts diagrams (14)

Browse saved diagrams & other models ↗

276 parts entries · catalogue coverage: MS 231, MS 231 C, MS 251, MS 251 C. Check the sheet’s variant and serial notes.

Model & family fitment specs

Actual displacement45.6 cc

Guide bar14–18″

Chain.325″ · .050–.063″

Bar mount3005 / A074

Displacement is specific to the MS 251 roster record. Chain, bar and mount are the published family fitment for engine series 1143; confirm the pitch, gauge and drive-link count stamped on your installed bar before ordering.

displacement · verifiedbar real-world · estimatedbar mount · sourcedchain · sourceddates · verifiedvariants · sourced

Chains & bars that fit the MS 251

Pitch & gauge .325″ · .050–.063″ · recommended bar 14–18″ · bar mount 3005 / A074 · round file 3/16" (4.8 mm)

Replacement chain → Guide bar · 3005 →

Chain & bar by length

Bar	Drive links	Shop
16″	67 DL	Chain → Bar · 3005 →
18″	74 DL	Chain → Bar · 3005 →

Drive-link counts come from STIHL's saw-chain catalog. Bar searches include mount 3005 / A074; still confirm the mount stamp, pitch, gauge and drive-link count on your installed bar before ordering.

Files, oil & sharpening

Round file 3/16" (4.8 mm) → Bar & chain oil → 2-in-1 sharpener →

Suggested match: Oregon 95-series (95VPX) / 21–22 LPX. Confirm the drive-link count for your exact bar length before ordering. These are equivalent aftermarket (Oregon) chains, not genuine STIHL chain — STIHL sells its own chain through its dealer network, and we're not affiliated with STIHL. New to fitment? See the bar-mount identification guide and chain & cutter guide.

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Service & tuning

Factory tuning settings

Idle speed	2,800 rpm
Max speed	13,000 rpm
H screw (high speed)	3/4 turn
Confidence	sourced

Screw figures are turns open from lightly seated. Set the final mixture by ear and tachometer against the machine in front of you — running a two-stroke lean to hit a published number is how pistons get scored.

About the MS 251

Production2011→now

MarketGlobal

RarityCurrent / Very Common

Engine family1143

Family era2011→now

45.6 cc

Production, market and rarity are specific to this model’s roster record.

Shared engine-family membership does not establish parts interchangeability.

Data confidence

Chain, bar, mount and displacement confidence comes from the shared MS 231 · 241 · 251 family research.