Be very aware, that if you remove any of the oil lines they will need to be bled free of air before you start the motor.
The complete oil system must be air free.
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Carb overflows are caused by,
Incorrect float level.
Needle not mating with seat because of wear, dirt or varnish.
The rubber O ring under the seat cracked or broken.
Leaky float with fuel inside.
Float supporting posts may be ridged, causing float to stick.
Float rubbing against bowl not allowing movement.
Float arm pinching on pivot bar.
If the float level is correct, does the fuel shut off fully when the float is gently lifted with a finger, with the fuel bowl off?
Float height is 20 to 21.5mm.
If so the problem is not with the needle and seat assembly and may be a mechanical problem, like the float sticking.
Not only spray jets, use a bit of wire broken from a wire brush to poke any debris out, especially the pilot as it has some very small holes in the side.
Remove the seat from the carb, and thoroughly clean the passage where the fuel line comes in.
Make sure the rubber O ring on the seat is not broken.
Put some toothpaste on a Q tip and revolve it up in the seat , to clean out any varnish.
Re assemble and check the float level, 20.0 to 21.5mm on a stock carb.