I agree, there is a voltage leak somewhere. I outlined measuring 'dark current' in a similar post here or on the Super Tenere forum some time back.
Do you by any chance have a SWMotec powered tank bag? If installed the way the directions are, direct to the battery, it draws current even with nothing turned on, just the bag on the tank ring. And will kill the battery quickly. BTDT. It needs to be wired to switched power instead.
I messed up the original post, edits to correct my errors. Thats what I get from not looking it up again.
As for testing dark current, or parasitic draw with the key off, take a multi-meter, set to AMPERAGE
in the 10 or 20 amp range
and do the following:
Loosen the NEGATIVE
terminal so you can easily pull it off. Touch the DMM probes to the terminal and the same battery post, note the reading, which should be 12-14 Volts, then with the probes staying connected, slide the terminal off so that the DMM is now in series with the removed terminal and the battery post. I've forgotten the Ma that spec is, but post what you find and it will be immediately apparent if it's too high. Should be around 45-54 Ma. Much higher than that indicates a problem.
And yes, the battery should easily last two weeks.