I have recently been bucking up the trees that I had felled on my property. For the smaller stuff I've been using my Redmax G5300 (same as Husqvarna 353e) with 20" bar. After burning a tankful of fuel doing nearly continuous cutting, I stopped to refuel. When I opened the oil tank, I could see that the oil was boiling. The oil tank is right beneath the muffler and the air temp was in the mid to upper 80s. I'm not really concerned, just wondering if anyone else has experienced this.
Reading elsewhere reveals that the 353 e-Tech came with a catalytic muffler. If the G5300 has the same, this could account for more heat from the muffler.
The cat muffler is likely the cause. First thing I did with those saws is replace the muffler with a non cat version, I then open that one up too.
Any chance the muffler has a leak, blowing hot exhaust gases on the case below? Something I've seen done, take the muffler off and use sticky back heat shield all over the case below the muffler to help keep heat from the case. I personally wouldn't keep running it like that.