My Stihl 024AV chain saw recently began to bog down when put under load after being used for a while. When first stating, it runs fine, but after about 10-15 minutes of cutting wood, it bogs down when put under load. I have thoroughly cleaned and inspected the fuel tank, filter and carburetor, to no avail.

Don H, August 2009

Check to see how soft your fuel line is. Sometimes the fuel line starts to degrade and it becomes very soft and can suck flat. It will most likely suck flat at sharp bends. A fuel line is only about $8 USD. If the saw is older and you have never changed the fuel line it might be it. I have had it happen to me. Also when the fuel line degrades like that, it can pull chunks of the line into the screen in the carb. Check your coolings fins as well. May be overheating. How old is the saw? I don't know if it has points and condensor. If it has points and condensor the condensor can get hot and break down. I know the older 028 do this and can be converter to solid state cheaper than buying a condensor.

David Trowbridge, October 2009

I'm not an expert but I found on my older model John Deere the recommended gas/oil mixture is very important.A guy at a small engine center recommended a 40:1 mix they use in all their equipment but this overheated my saw and it acted just like yours.[Mine was supposed to be 28:1].

Colin R, August 2009

Keep the air filter clean, and adjust the carb screw marked H a quarter of a turn out more than recommended.

John, August 2009