STIHL Injection (i)
STIHL injection technology enables the MS 500i to achieve extremely high performance with extraordinarily low displacement and low weight. The saw uses innovative technology to achieve rapid acceleration from 0 to 100 km/h in an unbelievable 0.25 seconds. The powerful saw is ready to use right away. Sensors measure air pressure and internal and external temperature, and pass information on to the control unit. This can use the identified values to determine the optimum fuel quantity and ignition timing.
Best power-to-weight ratio
Its revolutionary chainsaw engine technology, and resulting intelligent lightweight construction result in the best power-to-weight ratio on the market. The optimised design – with lightweight sprocket cover, more compact engine unit, flywheel with a low design height, and a reduced-weight crankshaft adapted to the low weight of the flywheel – makes work significantly more comfortable. The MS 500i is ideal for heavy timber felling, cutting into lengths, and pruning.
The decompression valve is part of the easy starting system. The valve should be pressed before starting to reduce the compression pressure when starting, as well as reducing the effort needed to pull the starter rope. The decompression valve is semi-automatic; it must be pressed manually before starting, but then closes automatically.
Sensor-controlled fuel metering
In addition to the external temperature sensor, the MS 500i also has a pressure and internal temperature sensor in its engine. This measures the environmental pressure on start-up, and during operation it checks the engine temperature and pressure in the crankcase. The electrical voltage generator delivers the required speed information. The control unit processes these values, meaning that the system adapts to the conditions of use. The fuel is then dosed at the optimum level, quickly resulting in perfect running characteristics.
Very easy to start, whether starting from cold or
The starting process is perfect, with no need for a start position, and easy access to the purger.
1-in-4 channel technology. The economical STIHL 2-MIX engine with 1-in-4channel technology features a high torque over a wide speed range. The chainsaw provides fuel savings of up to 20% compared to STIHL two-stroke engines in the same performance class without 2-MIX technology. Exhaust emissions are reduced by up to 50%.
Intense vibration at the handles of power tools can lead to long-term effects on blood vessels in the hands and arms. STIHL has therefore developed an effective anti-vibration system whereby the oscillations from the machine's engine are dampened which significantly reduces vibrations at the handles.
HD2 filter with radial seal
The new HD2 air filter, made from PET material and featuring a radial seal, prevents the intake of fine dust particles. The hermetic seal increases the service life of the engine and reduces wear.
When changing the cutting attachment, you will not risk losing the nuts on the sprocket. The MS 261 is the first STIHL chainsaw to be equipped with the captive nuts. A great advantage for all users.
Marking has been added to the fan housing to assist with plunge cuts. This ensures better directional control and safe use of the machine during plunge cutting.
Optimised bumper spikes
The tooth length of the bumper spikes has been adjusted to account for the radial contours of trees. The saw bites into wood even better when cutting lengths and felling.
Side chain tensioner
The tensioning screw can be found on the side of the chain saw through the sprocket cover. This removes the need for contact with the sharp saw chain.
STIHL ElastoStart reduces the shock caused by the compression of the engine during starting. The compression shock is taken away from the user's joints and muscles through a spring or rubber element in the starter handle.
Tool free filler caps
Special catches on the fuel and oil tanks for easy opening and locking without the need for tools.
Optimised sprocket cover
The flatter, narrower sprocket cover with integrated slide rails reduces effort when pruning and ensures outstanding chip removal.
STIHL Ematic with new oil pump system
The new oil pump system allows a higher volume of oil to be delivered. This is especially useful in dusty conditions or when using a long guide bar.
Power output kW/bhp
Weight kg 1)
System weight kg 2)
7.47 / 7.78
Power-to-weight ratio kg/kW
Sound pressure level dB(A) 3)
Sound power level dB(A) 3)
Vibration values left/right m/s² 4)
Tank volume l
Side chain tensioner
Sprocket - number of teeth
Cartridge filter HD2
4 channel / chrome
Oil tank volume cm3
Anti vibration system
Tool-free tank cap
ElastoStart / manual fuel pump (purger) / non-return ignition / decompression valve / stop button
EPA Certified fuel consumption l/h
1) Without fuel, without bar and chain
2) Unfueled, with guide bar and saw chain
3) K-factor according to DIR 2006/42/EC = 2.5 dB (A)
4) K-factor according to DIR 2006/42/EC = 2m / s ²