You drill it and open it more. If I had to guess its to get more flow without having to worry about it vibrating out. Also no matter how far you open a valve if the initial port is too small it will just lean out.
Ive done this to 2 carbs and the before and after is extremely noticeable.
The air cooled and the 80cc never really made its way over to the us. And if it is tag its for sure a fireball 125. If the head is black it is the the newer motor. Then it all comes down to ignition and clutch style. If its got the sudper clutch and easy start its the newest version. If it has the old ignition but “newer style clutch but with friction material its one version older.
it sounds like eitheryour tightening the bolt on the bottom of the steering shaft too tight. You have a bent steering shaft or a seized uniball bearing. If the steering shaft is hitting the uniball housing when turning the wheel then something is definitely bent.
