Find a place to mount one of those tool kit tubes with the screw on lid, and the size that holds a 1 liter fuel bottle,
One liter of fuel would be/should be enough to get you back home. Recommend you fill it with pure, 100% gasoline as it has
a better shelf life.
Here's a dude who sells the whole setup, but you can get those tubes just about anywhere:
http://thetooltube.com/ToolTube.html