I have been using a Husqvarna 240 chainsaw for almost 10 years after my Homelite XL chainsaw finally died. The Husqvarna is lightweight, handles well, has good anti-vibration mounts, and basic safety features. The fuel and oil fillers are on the side, making refilling easy,. It also starts well, until it doesn't. According to the small engine repair shop I use, Husqvarna's are prone to "flooding".
The choke is an important part of most small engines. "Pulling the choke" typically actuates a butterfly valve in the air intake, restricting airflow to deliver the richer fuel/air mixture required to start a cold engine. Once the engine has warmed up, disengaging the choke delivers the correct running fuel/air mixture. On a Husqvarna, pulling the starter cord with the choke engaged just once after the first "cough" is enough. A second pull can result in too much fuel in the cylinder, preventing combustion. The tricky decision comes when refueling the chainsaw and sharpening the chain. Has the engine cooled off enough that it needs half choke or full choke? If it does not start with the choke disengaged, should I try a few more times before adding choke and potentially flooding the cylinder? The Homelite was much more forgiving.
Where does "good design" come in? I purchased a Ryobi pressure washer with a Honda GCV engine and was surprised that it did not have a choke. It has a thermostat between the carburetor and the engine that automatically adjusts the choke based on the engine temperature - the YouTube clip https://www.youtube.com/watch?v=ssccIEUqvSM shows how it works. Automatic chokes have been standard on cars for years, but so far the only chainsaw that comes with an auto choke is the ECHO CS-3510AC.
To be fair, automatic chokes on small engines get bad press when they fail. On the other hand, I have flooded the Husqvarna so badly that I took it in for repairs thinking it had failed. The trick to clear a flooded engine is to disengage the choke, fully open the throttle, and pull the starter repeatedly. Of course, after many minutes of cursing, it is easy to think that maybe the chainsaw really needs to be choked.
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