How far do you guys fill your tanks? I think the book on mine says 1" below the filler neck. Does that mean below the filler insert, or to the bottom of the insert? I generally fill mine to the bottom of the insert. Just wondering what you guys do.

 

About 1 inch below the insert at the most.

 

right to the bottom of the insert.
only problem I've ever had is filling it up to the top and parking it in the hot sun. the heat caused the gas to expand and seep out of the cap.

 

I fill mine all the way up. I start with the high side and then fill the low side.

 

Part way up the neck on my FLHS, every drop I can reasonably squeeze in!

 

Unless it Hot out and I am not going to ride right away. I would leave a little room for expansion. As pjb brought up.

 

I do realise that - bought this bike new in 1990!

 

That doesn`t make sense, because you can have an overflow filling the high tank first, which cannot happen if you fill the low tank first.

The safe way is to fill the low side first, then the high side.

 

I disagree the gas you put in the high side is flowing to the low side from the start and if you fill it up to the neck then shift over to the low side a small amount will have drained to the low side (gravity) when you have finished filling the low side the high side will be just a little bit lower than it was when you stopped you stopped filling it.

It has been my experience that if you fill the low side first that is when you get the overfill. (yeah i have done it)

 

I wasn't trying to correct you Graham, just agreeing with pjb. If I am going to go riding right after filling up I will fill it as much as possible. I have a habit of filling my tank when I go home and park. Then I leave a little room in the tank .