If the plunger in the regulator is not seating, it will let the carb fill with fuel. It is not normal for the carb to flood if the engine is off. I had a 63 drip on me and there was no trash under the plunger. I marked where the regulator screw was, turned the regulator in all the way then back out to where it originally was and the drip stopped. Still running perfectly 3 months later and no drips. I do release the pressure after each flight, but if I don't, it won't drip.

As for the original guy..it just sounds like he's trying to run his engine too rich. YS 4 strokes hate being too rich.