Description
Overview:
The Pump Diaphragm is a genuine Stihl OEM replacement for the carburettor fuel pump circuit, supplied under MPN 4149 121 4800. It is a thin, flexible, fuel‐resistant membrane that meters and moves fuel within the carburettor to maintain steady running, reliable starting, and clean acceleration. Designed for Stihl handheld machines such as the FS 94 and FS 94 C brushcutters, it restores correct fuel delivery when the original diaphragm has become stiff, worn, or damaged through age or fuel exposure. Suitable for professional and domestic users, this part supports dependable day‐to‐day operation in grass cutting and trimming tasks. As a Genuine Part, it matches the original specification for fit and performance and installs during a standard carburettor service.
Key Features:
- Genuine Stihl part for correct fit and function (MPN 4149 121 4800)
- Restores reliable fuel flow, improving starting, idling, and throttle response
- Fuel‐resistant construction designed for long service life in small two‐stroke engines
- Direct replacement for worn or hardened diaphragms; no modification required
- Stable running under varying loads and positions typical of handheld tools
- Helps resolve symptoms such as surging, hesitation, and poor restart after storage
- Straightforward to fit during carburettor maintenance with basic tools
- Built to Stihl's OEM standards for consistency and durability
- Suitable for brushcutters, hedge trimmers, and Kombi units listed below
Typical Applications:
Used during routine servicing or repairs of Stihl carburettors when engines are hard to start, won't hold an idle, or bog under load. Ideal after long storage or when ethanol exposure has aged the original diaphragm. Common in landscaping, grounds maintenance, forestry support, and domestic garden care.
Also known as:
Pump membrane, carburettor pump diaphragm, fuel pump diaphragm, purge/pump diaphragm, primer pump membrane, replacement diaphragm for Stihl carburettors.
Fits Models:
FS 94, FS 94 C, FS 94 R, FS 94 RC, HL 91 K, HL 91 KC, HL 92 C, HL 92 KC, HL 94, HL 94 C, HL 94 K, HL 94 KC, KM 94 R, KM 94 RC, SP 92 C, SP 92 TC
Alternate Part Numbers:
4149-121-4800, 41491214800
Product Specifications
| L&S Part No. | 4149 121 4800 |
|---|---|
| Part Type | Genuine Part |
| Manufacturer | Stihl |
| OEM No. | 41491214800 |
| Unit of Sale | 1 |
| Applications | FS 94, FS 94 C, FS 94 R, FS 94 RC, FS94, FS94 C, FS94C, FS94R, FS94RC, HL 91 K, HL 91 KC, HL 92 C, HL 92 KC, HL 94, HL 94 C, HL 94 K, HL 94 KC, HL91K, HL91KC, HL92C, HL92KC, HL94, HL94C, HL94K, HL94KC, KM 94 R, KM 94 RC, KM94R, KM94RC, SP 92 C, SP 92 TC, SP92C, SP92TC |
| Machine Type | Brushcutters |
| Fits Brands | Stihl |
| Fits Models | FS94, FS94 C, FS94R, FS94RC | KM94R, KM94RC | HL91K, HL91KC | HL92C, HL92KC | HL94, HL94C, HL94K, HL94KC |
