Stihl model · engine series 1143
MS 251 45.6 cc
45.6 cc
The production, market and rarity details above are specific to the MS 251 roster record. The displacement below is specific to this roster record. The 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.
Model & family fitment specs
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)
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
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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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.
Parts diagrams (14)
276 part numbers. The catalogue files these under the MS 231, MS 231 C, MS 251, MS 251 C, one bill of material covering this model.
Related models in series 1143
Data confidence
Chain, bar, mount and displacement confidence comes from the shared MS 231 · 241 · 251 family research.
Something wrong or missing for the MS 251? Report a correction →