I took mine apart last year to clean it and it leaked afterward. So I paid $16 for a gasket kit to get the $0.25 o-ring I needed to fix it; it stilled leaked after. But it only drips and once I shut the valve stops in a minute.
I though about fixing it again, but it never has run so good so I haven't. I think that the carb leaking the fuel out after each use as been good.
stop blowing smoke up my rear, blow it at the sails instead
The only probable reasons for carb overflows are a bad float and/or a bad float needle. Easily done, best to replace both at the same time. It is also possible there is a speck of dirt on the needle valve seat.
And clean it out, as Tellie suggested, while you are at it.
"Climbing (sailing) is like fun, only different."