So I filled up and toped the tanks pretty good, then went inside for a bite. When I came out there was a 12"spot under the kick stand of gas. it was running down from where the split tanks mount to the frame. I wiped it all down and drove it to a local Indy (A cool dude on his chopper saw me at the station and lead me to this shop, Old Harley dudes appreciate old Harley bikes and everyone of them has been super cool this trip). Anyway, when I got to the shop (which was closed) I noticed all the dripping had stopped and it was dry. I drove it to a hotel and have been checking since and no more gas.


Is there a vent hole at the top of the tanks or something and I just filled it too high? I am more concerned of having a crack in the tank at the mount. Visions of one half of the tank falling off like a drop tank from a WWII plane keep creaping into my head....

 

My 2001 Springer will do the same thing it I overfill it.

 

You didn't say what year bike, but the only vent should be in the cap. Gas will expand and run out of a full tank if you let it sit. If it happens again, maybe sprinkle some baby powder to track down the leak?

 

Split tanks have a cross over tube at the top under the dash. If the tube is split or missing it could cause your leak if over filled.

 

It "could" be that the tanks broke at the front mounts and gas is leaking.... and when you ride the gas level just goes down...
it happened to me many years ago with 2 sets of tanks (unbalanced motor) and for a while I just didn't fill it all the way up

 

Check that first. Easy fix. If your tank is slightly cracked at the front top mounts it will need some attention...or just don't fill it completely up.

 

Sounds like you overfilled it.