i have a 1957 TO-35
it has the tsx 605 carb.
it has been rebuilt and the tractor runs great, idles at 400 rpms. takes the fuel fine and runs at top speed smooth.
it is a little cold collared or it has to be choked some on a cold start, but as soon as it warmed up some it runs great.
But!!!!! I always cut the fuel off to the carb at the fuel shutoff valve. i have had it off a few times over the years replace the needle seat, but i have never completely stop it from leaking fuel if the tractor motor is off and it is left for a while.
most times it's not a problem, but i do not trust it, so when i stop for lunch or away from the tractor for a period of time, I always shut the fuel valve off.
main reason: lose fuel, but the real problem, if you try to start the tractor with the carb and air inlet hose full of fuel you will draw raw fuel into the cylinders and you wash oil off the sides of cylinder and could cause them to scar.
So, if my tractor carb has leaked fuel: i drain the carb and air inlet hose before i try to start tractor.