Husqvarna chainsaws are reliable and powerful forestry tools used throughout the world. They have benefited from almost 100 years of experience and from engineering expertise from their parent company, BMW. However, heavy use can cause its thermal dissipation capabilities to be overloaded, resulting in a stalled engine. This can be rectified easily, though it requires some patience, as forcing the engine to cool down too fast can crack the radiator.
Remove the chainsaw from direct exposure to the sunlight. Place it in the shade or in an air-conditioned environment. Turn the choke to "shut" and slide the engine control to "off." Inspect the chain for any debris that may potentially be clogging the gear. The chain should be laying flush against the support (the long, metal extension from the engine that the chain rides on). There should be no rocks or sticks stuck under the chain or in the blades themselves.
Wait for 20 minutes to allow the chain saw to cool down. Do not adjust the choke, just press the fuel bulb twice to prime the ignition chamber. Slide the engine control to "on." Press and hold the throttle interlock, which is the top trigger on the handle. While still holding the throttle interlock, press and hold the throttle trigger--the bottom trigger on the handle--to halfway. The throttle will now stick at the level.
Take your hands off the throttle (it will stay put) and put your left hand on the front grip. Then put your right hand on the starter pull handle. Plant your feet firmly on the ground and then grasp the handle on the starter pull. Pull the handle back far enough till you hear the gears engage. You will also feel a slight increase in resistance.
Pull sharply back on the starter handle, stopping before the full extension so as to avoid breaking the rope. If the engine does not start then pull once more after allowing the rope to reel back in. The chain saw should start now. If not, the motor may have heat damage and needs to be taken to a mechanic.