|There are many maintenance evolutions where you will be working under the fuel tank. The Service Manual and many other farkle pages around the 'net often show the fuel tank being propped up by a wooden stick, long-handled hammer, etc.|
The problem with this arrangement is that it's possible to knock over the prop as you are wrestling with some component, resulting in the tank crashing down on your hands. Not good.
A much better, more stable approach is to use an appropriate length of nylon rope and simply tie the ends around the frame crossmember under the pillion seat, and loop the rope around the underside of the tank under the forward position (where the two 10mm fasteners normally go).
This results in the fuel tank being propped up in a secure, stable manner, and no wooden sticks or other propping device to get in your way of spark plug removals, throttle body syncs, valve adjustments, etc, etc: