Here is what's happening. Like it was told me, the saw starts and runs nicely. Idles, trottles up, etc. looks to have lots of power. But after cutting a few minutes, she stalls. It almost seems like the chain brake engages and stalls the saw. Basically, similar to when you engage the brake and throttle up the saw.
I don't believe the brake engages, but that's how the engine acts. The chain stops and the saw stalls.
So, is it a clutch issue, brake, carb ? It's not a fuel vent problem.