Curvy Fuel Leak

Hello all,

As stated my Curvy has a fuel leak. It's apperent to drink from the rear carb, however I just changed this with a known working and the leak is still there.

Now I checked all the lines when the previous carbs were on and nothing perished /seemed blocked. I'm thinking though that this could be the carb overflow as there's a good amount dripping out. Did a search and I think it could be the Tank Breather for the rear carb?

If anyone could narrow down the problem for me that would be great as I don't get much time at the moment with work and all.

Thanks.
Rory.

Any suggestion would be helpful.

I can't see anything that would suggest this problem with two sets of carbs in the exact same place...

Leak flowing down from the rear carb bowl cover. Re-sealed the old carb bowl 3 times and thought it was just knackard. But is the same for this known working carbs, so can't be bowl seals...