Anything and everything GT6.

Hi,
I am after some help regarding a petrol leak on my mk2 Gt6. After running the engine (ticking over on my drive) a small amount off petrol appears under the car. On further investigation it appears that the petrol only starts leaking a couple of hours after the car has been parked up and it appears to be leaking from around the mixture adjustment screw on the front carb (Both carbs mixture screws are wet with petrol all the time). The car has got an inline fuel filter fitted which I observed fill with petrol after the engine had been turned off (over an hour or so). I think the engine is running rich but it does seem to run okay once warm with only the odd small cough from the carbs. Could this leak be a result of bad setting up or is it more likely that some seals and o rings need replacing ? Any help as to what is best to check first would be great as I have little experience and am on somewhat of a steep learning curve !!

P.s The car is fitted with pancake style air filters but I not sure if any changes have been made to the needles.

Cheers

Ed.