Daft question, but it isnt that your just using it too much and its getting hot and fading is it?, either that or your using cheap ass pads…
Other than that, the best thing i could suggest is to remove the caliper (dont forget to put something in between the pads to keep them apart for when you accidently press the pedal!) and sit it on the seat, give the hose a good tapping with a screwdriver to try and move any trapped air upwards (towards the caliper)and then making sure that pads are held open (piece of wood same thickness as disk works great) bleed the brake whilst holding the caliper so that the bleed nipple is at the highest point. If it’s got twin pots (i aren’t sure) do one, then turn over so other nipple is at highest point. Reapeat a couple of times just to make sure….
GSX750 Ratfighter / SR125 Rat / GSX600F / Beamish250 / Honda70 Rat / Honda250 Rat Racer
Blackboard paint – Covers a multitude of sins!