starts then dies when hot

I have an echo CS-4600 that dies and has a difficult time restarting after getting hot. I only get about 1-2 minutes of use before it starts this behavior. Once I get it restarted after it gets hot, the motor bogs/dies when throttle is applied. Additionally, the saw will die when idling after it...

I have a 4 yr old MS291 that fells and bucks 25-30 trees/yr. I run only non-ethanol 91 and Stihl oil. Ran saw yesterday for the first time this year, fell and bucked one tree, cutting second tree, saw was good and warm and sputtered out. I could get it to start, but not run, would die under...