The STIHL MS 391 is a high-powered, rugged chainsaw built to handle the biggest jobs on the field, farm, and ranch. Engineered with advanced engine technology, it delivers high fuel efficiency and reduced exhaust emissions compared to other models. While it shares the same weight as the MS 311, the MS 391 packs significantly more power, offering an optimal power-to-weight ratio that makes storm cleanup, tree felling, and firewood processing faster and easier.
Driven by a 64.1 cc engine producing 4.4 bhp, this chainsaw is a true workhorse. It features a sophisticated air filtration system and specialized comfort controls designed to keep you productive during long days of heavy-duty cutting.
Key Features & Benefits
High-Performance Engineering
- IntelliCarb™ Compensating Carburetor: Automatically adjusts the air/fuel ratio to maintain the engine's correct RPM, even as the air filter becomes restricted or partially clogged.
- Pre-Separation Air Filtration System: Uses centrifugal force to eject heavier dirt particles before they reach the filter, doubling the time required between cleanings and extending engine life.
- Advanced Engine Technology: Provides higher fuel economy and longer run times, saving you money on fuel while reducing environmental impact.
Operational Comfort & Control
- Anti-Vibration System: Minimizes the vibration levels of the handheld equipment, helping to reduce operator fatigue and provide a more comfortable working experience.
- Master Control Lever™: A convenient single lever that operates the choke, starting throttle lock, and on-off switch for simplified operation.
- Side-Access Chain Tensioner: Allows for much more convenient chain adjustments using a bar wrench from the side of the housing.
Durable & Safety Focused
- Toolless Fuel and Oil Caps: Featuring easy-to-lift levers, these caps allow for fast refueling and oiling without the need for tools.
- High-Tech Polymer Housing: Built to be lightweight yet durable and corrosion-resistant, ensuring the saw can withstand years of hard use.
- Bumper Spikes: Provide better control and prevent pull-in, making every cut more stable and predictable.
- Throttle Trigger Lockout: A vital safety feature that must be depressed before the trigger can be activated.
Technical Specifications
| Intended Use | Farm / Ranch |
| Displacement | 64.1 cc |
| Engine Power | 4.4 bhp |
| Powerhead Weight | 13.7 lbs. |
| Fuel Capacity | 20.3 oz. |
| Chain Oil Capacity | 11.8 oz. |
| Recommended Bar Length | 20 in. |
| Chain Type | 3/8" RS3 |
