CT70 Replacement carb recomendations

[two-stroke-brit]

hi all, i am working on a buddys 1974 ct70.
it has a 70 main jet which is too rich and fouls plugs quickly.
i changed it to a 60 and it wont run without choke.
i have ultra sonicly cleaned the carb several times.
i am thinking the carb is just worn out.

is there a goto replacement carb.

TIA mark

 

[cjpayne]

It supposed to have a 58main. Running with the choke on is a dead givaway that something is off. Is there a cone filter on it? Something is letting in to much air.