STIHL has developed a system for minimizing the vibration levels of handheld outdoor power equipment. The STIHL anti-vibration system helps reduce operator fatigue and provides a more comfortable working experience.
Technical details
| Displacement | 3.9 in³ |
| Power | 4.4 BHP |
| Device weight without refuelling | 13.8 lb 1) |
| System weight without refuelling | 16.7 / 17.0 / 18.5 / 16.2 lb 2) |
| Power-to-weight ratio | 3.1 lb/hp |
Features
The pictures shown are sample photos. The actual appearance of the equipment features and their specific attachment to the product may differ from the pictorial representations, but will have the same functionality.
These spikes prevent pull-in and provide better control, making cutting easier.
Housings are lightweight, withstand greater impact, and are corrosion-resistant.
The IntelliCarb™ Compensating Carburetor is designed to automatically adjust the air/fuel ratio when the air filter becomes restricted or partially clogged and maintains the engine’s correct RPM. IntelliCarb™ uses air from the clean side of the air filter to control the diaphragm and flow of fuel. As the air filter becomes dirty and less air is available for the carburetor, the IntelliCarb™ system adjusts the fuel flow to compensate for the decrease in air flow. This is in contrast to typical carburetors that utilize this air from the “dirty” side of the air box.
The Master Control Lever™ is an easy to use single lever, operating the choke, starting throttle lock, and on-off switch. The operator must pull the throttle trigger before moving the Master Control Lever™ to the choke position.
This time-saving technology boosts the efficiency of the engine’s filter system, doubling the time between air filter cleanings. Air drawn into the engine is first separated via centrifugal force, ejecting the heavier dirt particles before being routed to the air filter. This pre-separation means less dirt to be captured by the air filter, resulting in less frequent cleaning and maintenance.
The side-access chain tensioner makes it much more convenient for the user to adjust the saw chain with a bar wrench as opposed to the typical location of the guide bar adjustment screw.
This safety feature must be depressed before the trigger can be activated.
Simply lift the lever and twist the caps to remove or tighten. There’s no need to use a tool to tighten or loosen.
This mid-range chainsaw comes with an anti-vibration system and reduced exhaust emission engine technology.
The STIHL MS 391 is built for the big jobs around the field, farm, and ranch, delivering the power to take on felling trees, cutting firewood, and storm cleanup with confidence. More powerful than the MS 311 at the same weight, it offers an optimal power-to-weight ratio for strong cutting performance without added weight. Bumper spikes help prevent pull-in and provide added control while cutting, while the side-access chain tensioner makes it convenient to adjust the saw chain with a bar wrench.
STIHL engine technology helps reduce fuel consumption and exhaust emissions while delivering longer run times, so you can keep working when there’s plenty of cutting ahead. The IntelliCarb™ Compensating Carburetor automatically adjusts the air/fuel ratio to maintain the correct RPM, while pre-separation air filtration doubles the time between air filter cleanings. Toolless fuel and oil caps make refueling and adding bar and chain oil more convenient, with no tools needed to tighten or loosen the caps. Rugged, efficient, and designed with practical features that keep the work moving, the MS 391 is ready for demanding cutting jobs season after season.
Hazard Warnings
E-10 Statement
Note: STIHL recommends use of fuel with no more than 10% Ethanol content. Using fuel with greater than 10% Ethanol content may cause damage to your equipment and may void your STIHL warranty.
Proposition 65 - EnglishThis product contains chemicals known to the State of California to cause cancer and reproductive harm. www.P65Warnings.ca.gov
General Power ToolImproper use of any power tool may cause serious or fatal injury. Read, understand, and follow carefully the operating and safety instructions in your instruction manual before using such products. STIHL products sold through U.S. STIHL Dealers are for distribution in the United States only. Improper use of any power tool may cause serious or fatal injury. Read, understand, and follow carefully the operating and safety instructions in your instruction manual before using such products. STIHL products sold through U.S. STIHL Dealers are for distribution in the United States only.
