Cap vent
I have a fairly recent kit,797 and have the tank vent. I didn't drill the vent in the cap originally. I have had three minor "events" during takeoff ,a strong fuel smell in the cockpit. The engine did not skip or stumble, just smelled fuel. I decided to drill the vent holes in the cap. I did, however drill with a #43 drill and tapped 4-40, so I can plug the hole with a 4-40 screw if I find I don't need the vent hole. I have 4 flights (6.2 hours) with the cap vented and no fuel smell yet. I will update as I accumulate more hours.