Triumph Repair: Fuel from bowl vent?, triumph spitfire 1500, vent lines

Question
Hi, I have a Triumph Spitfire 1500 with twin SU carbs. I recently cured a fuel starvation problem, blockage in the pipe from fuel tank to pump. After this a leak in the fuel pipe coupling under the car. I then managed to get the car fired up, bit of a leak on the pipe into the front carb which was cured by tightening the clip at the joint. Car appeared to run OK. Left for a week and then when taken out again, did not appear to warm up thoroughly, very lumpy without choke and then discovered fuel coming from the vent lines. These copper pipes just come from the carbs and are bent down next to the radiator and open to the air in my vehicle. Any ideas as to what is the cause. Thanks.

Answer
Could be:

0) float valve stuck open from debris from clearing your blockage
1) bad float valve;
2) high fuel pump pressure overcoming float valve

Normally vent lines to a charcoal canister and/or intake manifold vacuum; open to air like that would cause me a concern on fire risk...I would suggest checking plumbing diagrams on early spits to see how they routed the vent lines.