Stihl model · engine series 1122
MS 640 84.9 cc
- Chain
- 3/8″ · .063″ · .404″ on long bars
- Recommended bar
- 20–36″
- Mount
- 3003 / D025
Model displacement · family chain/bar fitment. Details & confidence ↓
Parts diagrams (13)
Browse saved diagrams & other models ↗314 parts entries · catalogue coverage: MS 640. Check the sheet’s variant and serial notes.
Model & family fitment specs
Displacement is specific to the MS 640 roster record. Chain, bar and mount are the published family fitment for engine series 1122; confirm the pitch, gauge and drive-link count stamped on your installed bar before ordering.
Chains & bars that fit the MS 640
Pitch & gauge 3/8″ · .063″ · .404″ on long bars · recommended bar 20–36″ · bar mount 3003 / D025 · round file 7/32" (5.5 mm)
Chain & bar by length
| Bar | Drive links | Shop |
|---|---|---|
| 20″ | 72 DL | Chain → Bar · 3003 → |
| 22″ | 76 DL | Chain → Bar · 3003 → |
| 25″ | 84 DL | Chain → Bar · 3003 → |
| 28″ | 91 DL | Chain → Bar · 3003 → |
| 32″ | 105 DL | Chain → Bar · 3003 → |
| 36″ | 114 DL | Chain → Bar · 3003 → |
Drive-link counts come from STIHL's saw-chain catalog. Bar searches include mount 3003 / D025; still confirm the mount stamp, pitch, gauge and drive-link count on your installed bar before ordering.
Files, oil & sharpening
Suggested match: Oregon 72/73/75 EXL. 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.
Some links earn us a commission. It never changes the specs or what we recommend.
Service & tuning
Factory tuning settings
| Idle speed | 2,500 rpm |
| LA screw (idle stop) | 1/4 turn |
| Confidence | sourced |
Screw figures are turns open from lightly seated. These are the figures every model in this family shares; an individual model page may be more specific. 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 640
EU large pro below 660
Production, market and rarity are specific to this model’s roster record.
Related models in series 1122
Shared engine-family membership does not establish parts interchangeability.
Data confidence
Chain, bar, mount and displacement confidence comes from the shared 064/066 · MS 660 · MS 650/640 family research.
Something wrong or missing for the MS 640? Report a correction →