If you suspect a residual load is draining your battery with the ignition off, then it would be worthwhile to measure the quiescent current being drawn from the battery at rest. Normally, the only circuit in-play with the ignition off is the clock in the instrument cluster (I'm making a big assumption here that your K75 is stock).
(1) Putting an ammeter in series with the positive lead of your battery and setting the scale to 100mA or so will show you the quiescent current. Couple of warnings: don't turn on the ignition or try and start the bike with this setup; you'll blow your meter. And the readings won't be accurate, only indicative, because of the burden voltage of the meter.
(2) If the wiring on the bike is stock, the quiescent current drain on the battery is tens of uA, very little. If the wiring has been modified by a PO, then you should start your diagnosis there, possibly be reversing the changes or eliminating the aftermarket accessory.
(3) If you have a reading anywhere more than a mA, there is something draining your battery. If not, then your battery condition is probably poor which is leading to your symptoms.
(4) I would pull all the fuses and see what the current draw is. If it is still high, the non-switched circuitry on your bike is the problem. Start tracing those sets of wires.
(5) If your K75 is a late model with ABS brakes, it's been known that the ABS relay can go bad and start to put a load on the battery with the ignition off. Pull the ABS relay and see if the current draw goes down. If it does, replace the ABS relay.
(6) If it's not the non-switched circuitry causing your problem, start to re-insert fuses in the panel and observe the meter. If you insert a fuse and the current draw goes up, the problem is in that circuit. Start your tracing to find the problem.