For some reason gas leaks through the vent holes and flows all over the outside of the tanks on both of my large neck gas caps when the tank is at least half full. Both caps are screwed down tight on the tanks and the gas is splashing up through the center vent hole. It's kinda of a pain having to run tanks at less than half full. Is there a redesigned cap available from Exmark? Thanks in advance, wwjam 2002 LazerZ 60"