How do you fix this problem

[Mr_RPM]

my 84 110 gas tank lid leaks. when riding with a fullish tank and going over rough ground or doing wheelies gas leaks from the lid. The gas normally runs down the back of the tank towards the seat.
i dont remember it always doing this, but i also realize its not going to be a perfect seal or air wouldn't flow into the tank. so is this normal? there is a o-ring in the lid that seem to be in good shape.
Im getting ready to line the gas tank with sealer and while im working on the tank im wondering what i can do to fix this problem.
anyone ever have this problem? any fixes?

its just there is always gas residue on the tank and collects dirt and makes me smell like gas after every ride.

[harryredtrike]

the lid seal is worn out and should be replaced number 8 is still available

[shortline10]

If the seal isnt dry rotted try flipping it over for a cheap fix .

[Mr_RPM]

ill try flipping it, test it (even though the trike is all apart, ill just slosh some gas around i guess) if it fails the ill just order that seal. thanks guys =)