[RobS]

Gonna guess on the stoppers: The fuel fill caps would leak so solid rubber stoppers (without holes) are placed in the filler neck before the fill cap goes on to catch any water that may make it's way through the cap. First I've heard of this but seems simple and effective if needed. What's nice is after a heavy rain, boat wash, etc you can remove the cap and check for water. Just not sure why a replacement o-ring on the caps wouldn't solve the issue...