STIHL Extension Tube for SR 450

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.
Decompression valve
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 hot
The starting process is perfect, with no need for a start position, and easy access to the purger.
STIHL 2-MIX-Engine
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%.
Anti-vibration system
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.
Captive nuts
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.
Plunge guide
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
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

Advanced combustion technology
Four overflow channels swirl the fuel-air mix before ignition, allowing for optimum combustion and highly efficient performance. The result is lower fuel consumption and high torque across a broad rpm range.
Anti-vibration system
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.
Pre-separation air filtration system
STIHL long-life air filtration systems with pre-separation achieve perceptibly longer filter life compared with conventional filter systems. Air drawn in is swirled. The larger, heavier particles are ejected. The pre-cleaned air is routed to the air filter via the pre-separator duct.
Compensator
This controller in the carburettor prevents the fuel-air mixture getting richer as the air filter becomes clogged. The correct quantity of fuel is delivered to the carburettor depending on the quantity of air passing through the air filter. This keeps the fuel/air ratio in the combustion mixture constant and hence also the engine power. The filter doesn’t need to be cleaned until an appreciable drop in power occurs.
Single-lever master Control
All important functions such as start, choke, throttle and stop are operated via a single lever.
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.
Ematic chain lubrication system
The Ematic chain lubrication system ensures pinpoint lubrication of the saw chain links and guide bar rails. When used with STIHL OILOMATIC saw chain, it will provide maximum lubrication, longer wear and less oil consumption than conventional methods of chain lubrication. The Ematic system can reduce bar oil consumption by up to 50%.
Tool free filler caps
Special catches on the fuel and oil tanks for easy opening and locking without the need for tools