Air in the lines. You'll need to vacuum bleed or reverse bleed to purge it.
Lots of folks (myself included) have had good luck tying the brake lever to the grip (full on position) overnight. Air tends to make the vertical travel and will be able to escape if the cylinder is open to atmosphere.
I know that people swear this is the bee's knees but you can do the same thing, purge the air out of the lines by the simple expedient of the reverse-bleed. No-need to wait for the Sugarplum Fairy to give your brakes a firm lever, overnight. Perform a reverse-bleed, feel the minimal lever travel to achieve a firm lever for your front brakes (or a firm lever for the clutch release) and go riding.
This link will explain the procedure and how you can make a tool to do it. Clutch or brake, pretty-much the same.
(1) Clutch slave cylinder replacement | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)
Just make sure you remove the fluid from the master cylinder as the reverse-flush fills-it. When you see the cascade of fluid make a solid column from the hole in the bottom of the master cylinder as you push the syringe at the caliper bleeder and there are no-more 'tiny little bubbles' (thank-you Don Ho) from that hole, you're ready to shut the caliper bleeder, and move to the other caliper, the one closer-to the brake master cylinder.
If your smaller master cylinder hole (the one closest-to the banjo bolt for the brake hose) is plugged, neither function will operate properly: front brake, nor the clutch, depending on which master cylinder is plugged-up.
To make bubbles rise overnight by tying-back the lever to the handlebar, try that, too, and see if you notice a difference.
