The chainsaw is once again ripping through
logs like a hot knife cutting through butter.
It turns out I was on the right track with suspecting the fuel as the
culprit. The key was in the symptom details. The engine sounded and
felt like it does just before it runs out of gas.
The only thing I did to get it to work this time was bring the fuel
canister in the trailer for a few hours before filling it up. I had
been storing it outside, which seems to be the root of my problem.
Maybe it has something to do with the oil and gas mixture? My
conclusion is to just keep the can of mixed gas inside along with the
chainsaw and everybody stays happy and warm.