DAN,STICK WITH THE 1/4 IN.LINE.I HAVE OWNED WAY TO MANY AIRPLANES,(SAYS
WIFE) AND THEY ALL HAD 1/4 VENT LINES.
YOUR JUST TRYING TO VENT THE TANK,NOT PRESSURIZE IT.
THIS IS ONE OF YOUR MOST IMPORTANT AREAS TO PREFLIGHT TO MAKE SURE MUD
DOBBERS OR ANY BUG IS NOT STUCK IN THE VENT.
ALSO A 3/8 LINE CAN ICE UP JUST AS FAST.AND A BIRD FEATHER COULD GET STUCK
IN IT.MAYBE WE WORRY TO MUCH?

KEN COVINGTON  E.S.