I got one for you guys. Check side diaphragm. The one that came out was the blue stiff plastic deal. To match that up I went against my better judgement and installed the same style in the black stiff plastic.
Saw would not transition from low to high at all. It could idle all day. It could run on fast idle start too. But to throttle from idle or fast idle to full throttle she would stumble and die.
I got it fixed 5mins or so later. My judgement was right. I pulled carb and stuck the tan diaphragm in. From now on tan 1st, black rubber 2nd and those stiff blue or black plastic ones last.
In my pea brain the checks are just to stiff in those. Trying to find the carb diagram to see if my theory inside the carb shows what I am thinking.
https://www.walbro.com/wp-content/uploads/2016/01/WTseries.pdf