I’ve only noticed yesterday, not much fuel would go through the petcock, due to junk, I cleaned it out and now it’s dripping rapidly. I haven’t started it up since I cleaned it out. I have no 2 stroke oil, although I just used straight petrol to test the flow (never went into carb)
Most petcocks will rotate with the handle pointing up at the tank for on or rotate down pointing at the carb, crossways pointing in or out is off. Try with the handle pointing up then rotate it 180* and see if there's a difference.
You are vapor locking. Un screw the gas cap and run it. If there is a notable difference, remove rubber ring on gas cap and drill several small holes around the outer edge on the inside, that is normally facing down . Dont drill the holes so that the rubber gasket will cover them when you put it back on. Keep adding holes until the gas flows freely.
It's easy to tell if your gas tank isn't venting. When ya take the cap off you'll hear a swooish of air
One 1/16" vent hole on the front of the filler neck will be enough to vent the tank
Or just drill one 1/16" vent hole right through the top of the gas cap
You really don't want several holes all around the filler neck gas will keep leaking out every time ya slosh the gas around in the tank