Yep that looks about right for a 90cc + saw running 50:1 a work saw actually getting worked that is. It would have to be tuned so fat constant 4 stroking under load running cold as and doing bugger all work for it not to look like this in a 90cc + saw running 50:1 this is the normal result but of course the common reply tuned lean must have air leaks crank seal gone on pto side blah blah etc is never the lack of oil in the mix for the actual work a saw is doing no matter the cc.
You can imagine how fast this happens over here in the middle of summer in 40°C/105°F heat.
I don't get the oil is bad way of thinking now days if a saw tunes nice burns clean runs cooler under load has more power last years and years with no failures with more oil in the mix how is that a bad thing? lol.. And I like the good old an air leak is instant death for a saw line truth is that would be no its not if you actually have oil in the mix the guys that have had a known air leak and kept running the saw know what I'm talking about but they sure ain't running 50:1 lol
Thought I'd add the more oil in the mix = carbon build up in the exhaust port and on top of the piston crown and it will break off and score the piston and/or bore so more oil is bad blah blah myth line.
The reality of this is carbon build up is thanks to way off tune nothing more! you can tune a saw to clean burn at any oil mix ratio thats fact (shock horror).
If someone has (I doubt anyone here has had the carbon problems) carbon build up it just means they cant tune a saw for crap! most I think get a saw in to fix and it has had carbon problems and say see to much oil and forget it has to do with tune not mix ratio.
Lets not forget the 40 year old McCulloch chainsaws and the guys that say see too much oil look at the carbon in the exhaust port and say see oil = bad! no kidding hey it's only been running for 40 or so bloody years most of that on 30w engine oil these things can happen after a generation or two lol.
So many myths and old wives tales not to mention guessing games when it comes to oil in chainsaws.