Hi, on my 1995 flstn I have a Pingel petcock on a 5 gallon split tank. I have to switch to reserve after using 2.5 gallons, is that how split tanks work on a Heritage or is it the Pingel valve ? I do fill both side when I gas up. Thanks in advance for any help with this question.
Thanks again, Jack

Jack,

Is your tank stock? It should have a balance tube that keeps both halves of the tank always equal. When you switch to the reserve then you are pulling from the very bottom of the tank.

If you have to add gas to each side, meaning you have 2 gas caps and each side is independent of each other than switching the petcock will drain one tank or the other.
IF you have one gas cap that fills both sides then you will have a balance tube.
If you have a balance tube system, the reserve is based on a 2 level petcock drain inside the tank.
Most reserves leave just a little under a gallon in the tank. when you switch the petcock into the reserve position it opens the lower inlet inside the tank part of the petcock valve letting the last of the gas to drain out.

Hey hardrider and roadking thanks for your help.

any time