With such a small gas tank, accurately knowing the fuel level is important.  The gauge works well, but it is not the model of accuracy.  Like many other folks, I kept a stick next to the driver's seat for use as a fuel dipstick.

After misplacing the stick one day, I got to thinking.  One of the biggest drawbacks to owning a lathe is that the answer to every problem is generally round and threaded:

 

The dipstick is 1/4" brass rod, and is threaded into the bottom of the fuel cap. Use only a non-sparking metal for the dipstick.  The length was determined by trial and error so it just missed vibrating against the tank bottom while driving.  I filled the tank, then marked the full level on the dipstick.  Since it is a 10 gallon tank, I divided the rest of the dipstick into 10 even sections.  A normal person could make notches with a file.  It must have been a slow day for me.  I put it back on the lathe and made knurled rings.  This dipstick has sure come in handy many times.