Dual fuel issue

[rage rover]

Hi , I've got an 82 rrc, running stock carbs and duel fuel. When I switch to petrol it fills the carb and then pours out an "overflow" line coming out the carbs-wtf? How do I sort it out?

[101RRS]

Petrol is pumped into the carbs that have floats etc but the fuel does not cut off when the chambers are full - the excess fuel flows back out of the carbies back to the tank via external pipes than join up to both carby over flows.

If you have fuel leaking then there is a crack in on of these pipes (or not there) or they are blocked preventing the fuel going back to the tank.

Garry